The Francon quarry ranks as the second most prolific type locality in Canada after Mont Saint-Hilaire. It has yielded ten new mineral species: weloganite, dresserite, hydrodresserite, strontiodresserite, sabinaite, franconite, doyleite (co-type-locality), hochelagaite (co-type-locality), montroyalite and voggite. Weloganite, described in 1968, established the quarry as a world-famous mineral collecting site. Weloganite was the first known zirconium carbonate, and remarkably, it occurs as attractive, well-formed crystals up to 6 cm in size. Ninety species have been documented from the quarry, mostly from the unique, dawsonite-rich carbonatized phonolite sills which are genetically part of the Monteregian Hills alkaline igneous province.
LOCATION
The Francon quarry is unusual in being located in the midst of a large metropolis, the city of Montreal, on the Island of Montreal. It is situated at latitude 45[degrees]34'20" N, longitude 73[degrees]36'50"W, in what was previously known as the Saint-Michel district, and is now part of the Arrondissement de Villeray--Saint-Michel--Parc-Extension (Borough of Villeray--Saint-Michel--Park-Extension). The quarry is shown on National Topographic System Map 31 H/12. The original entrance to the quarry was at 3701 rue Jarry Est.
Some confusion can arise from the fact that the last operator of the quarry, Francon (1966) Limitee, also worked the former Francon (Montreal-Est) quarry, (1) situated 8 km to the northeast, at latitude 45[degrees]37'14" N, longitude 73[degrees]32'06" W, in the municipality of Montreal-Est. The latter quarry is now called the Lafarge Carriere [= quarry] Montreal-Est. In order to avoid confusion, mineral labels for the Francon quarry should read Francon quarry, Saint-Michel district, Montreal, Quebec, Canada. In some publications Montreal Island appears as part of the locality designation. This is redundant and should be avoided.
HISTORY
As early as the 17th century the abundant outcrops of limestone on the Island of Montreal were being used as a source of building material and for the production of lime. By the 19th century, Montreal had become known as "the old gray city" because of the numerous public and private buildings constructed of local limestone (Collard, 1981). Since the end of the 19th century, the island's limestone has been quarried for road material, concrete aggregate, and the manufacture of cement.
Quarrying on the present site of the Francon quarry was begun in 1914 by the Quinlan and Robertson Company (Gauthier, 1919). Subsequent operators included the Arthur Dupre Company (1924-1928), National Quarries Limited (1930-1962), and Highway Paving Company (1963-1965) (Sabina, 1976). In 1966, the quarry was taken over by Francon (1966) Limitee, a division of Canfarge Limited.
Despite its long history, the quarry remained unknown as a mineral locality until 1966. The presence of sills of igneous rocks had been noted by Gauthier (1919) and later by Clark (1952) but nothing was reported on their mineralogy. The limestone on the Island of Montreal was not known as a source of mineral specimens, and like other limestone quarries the Francon quarry was ignored by mineral collectors.
On July 19, 1966, the quarry was visited by Ann P. Sabina of the Geological Survey of Canada (GSC) and a student assistant. The visit was part of a reconnaissance of rock and mineral occurrences of potential interest to collectors. During the visit, Sabina noticed the presence of cavities containing crystallized minerals in a particularly thick sill of igneous rock. Among them was an unusual looking mineral. As described by Sabina (1975) "it was the glow of golden yellow .... that caught the eye ... [and] it captured the attention of the field party." Investigations of the mineral revealed that it was a new species, ultimately named weloganite (Sabina et al., 1968). The discovery of weloganite, and the fact that it occurs as attractive, large crystals, captured the attention not only of mineralogists and mineral collectors, but of the press. The Montreal Star reported the discovery under the byline "Enter weloganite" (Anonymous, 1968). The Canadian Magazine published an article entitled "Another Canadian first! (Yes sir, it's weloganite)" (Alderman, 1968) which described the discovery in a tongue-in-cheek fashion, and profiled the GSC mineralogists who had described the new mineral: John Jambor, George Plant and Ann Sabina. Shortly after, in 1969, another new species, dresserite, was published (Jambor et al., 1969). Weloganite and dresserite were the first of the ten new mineral species described from the quarry between 1968 and 1990. All the type specimens, except for voggite, were collected by Sabina, and five were first found in her original investigation of the quarry.
With the publication of weloganite, the quarry quickly became a popular destination for mineral collectors and mineralogists from far and wide. Sabina also continued to routinely visit the quarry. The frequent visits by amateurs and professionals alike in a quarry where new sill sections, and indeed new sills, were being exposed by ongoing operations contributed to a growing list of mineral species. From about 40 minerals in 1976 (Sabina, 1976), the list had increased to about 60 by 1979 (Sabina, 1979), and currently stands at 90. Because the mineralization is not uniformly distributed throughout the sills, regular visits to the quarry were important in documenting unique occurrences, and in preserving many exceptional specimens. Instrumental in this was the continued cooperation of Francon (1966) Limitee in permitting access.
The development of the quarry was carried out along a northwest-southeast axis. The oldest section of the quarry is at the southeast end. When Clark (1952) visited the quarry between 1938 and 1941, quarrying had reached a depth of about 38 meters along the northeast wall. This corresponds to the floor of the present first level. When Francon (1966) Limitee took over the quarry, the first level had been quarried to the northwest property limit, and a second level with a bench height of about 25 meters was being advanced in a northwest direction. Because a crushing plant had been installed on the floor of the first level, the second level was developed some distance in from the southeast end of the quarry and was accessed by a ramp. This level is referred to in the literature as the "upper level." The first of the weloganite-bearing sills, the so-called "upper sill," was encountered when quarrying began on the second level around 1955.
By August of 1968 the second level had been excavated over an area of about 215 x 400 meters, with the sill exposed around the entire perimeter (Steacy and Jambor, 1969). At the bottom of the ramp, the quarry wall angled to the southwest, forming an offset that became known as the "alcove." By 1975, the second level had reached the northwest property limit, and a third level, referred to as the "lower level," was being driven on two sub-levels, from the northwest end of the quarry to the southeast. This revealed a second weloganite-bearing sill, the "lower sill." A third sill, not as well mineralized, was partially exposed at the very bottom of the lower level.
In 1981 the north half of the quarry was taken over by the City of Montreal for use as a snow dump. Quarrying operations continued at the southwest end of the third level for a time, and then moved to the alcove on the second level. The alcove was developed on two sub-levels with the benches being advanced to the southeast. This area became the focus of mineral collecting over the next several years. The alcove produced two new mineral species, montroyalite (Roberts et al., 1986) and voggite (Roberts et al., 1990).
When quarrying first started, the Francon site was surrounded by farmland. By the 1960's the quarry had been overtaken by urban development, with a residential area along its southwestern and northwestern perimeter and an industrial zone on the northeast side. In 1985, environmental issues and the exhaustion of economic reserves of limestone contributed to a decision by Francon (1966) Limitee to terminate quarry operations. The quarry was sold to the City of Montreal, which has continued to use it as a snow dump and solid-fill site. In recent years, the alcove was still accessible for mineral collecting. One of the last visits by Sabina was in 1992 when she organized a field trip for members of the Geological Survey of Canada as part of the celebration of the Survey's 150th anniversary (Sabina, 1992). Occasional field trips were also organized by the Club de Mineralogie de Montreal up until the end of the 1990's. However, with no fresh exposures of sill rock, collecting had become far less productive than in the heydays of the late 1960's and the 1970's. The quarry is now closed to collecting.
Currently the quarry measures about 2 km along the northwest-southeast axis on the first level, and has a maximum width of about 580 meters over the southern half, narrowing to about 380 meters over the northern half. On the third level the quarry extends about 1.5 km from the northwest to the southeast. The depth of the quarry in this section is about 80 meters.
At present, parts of the quarry are buried under fill and solid residues from melted snow. Much of it is now covered by trees and other vegetation.
REGIONAL GEOLOGY
The Island of Montreal is situated within the Saint Lawrence Platform, a thick sequence of Cambro-Ordovician sedimentary rocks resting on a Proterozoic basement. In the Montreal area the platform occupies the junction of the Ottawa-Bonnechere graben and the Saint Lawrence graben (Clark, 1972; Brisebois and Brun, 1994; Brisebois et al., 2003). These grabens were formed as a result of the supercontinental rifting which gave rise to Laurentia (the nucleus of the present North American continent) and to the opening of the Iapetus Ocean during the late Proterozoic (Kumarapeli, 1985; Rocher and Tremblay, 2003). The Saint Lawrence Platform is bounded on the northwest by the Proterozoic Grenville Province, and on the southeast by the Humber Zone of the Appalachian Province.
The sedimentary rocks making up the Saint Lawrence Platform were deposited on the continental shelf of Laurentia over a period of about 100 million years, from the early Cambrian to the late Ordovician. During the middle Ordovician, as the Iapetus Ocean began to contract, an island arc collided with the outer margin of Laurentia, initiating the Taconic Orogeny and the formation of the present Appalachian Mountains. The Humber Zone marks the western edge of the Appalachian Province. In the Montreal area, the Taconic Orogeny is manifested by low open folds in the sedimentary rocks.
By the Permian, Laurentia had become part of the supercontinent of Pangea. Subsequent continental rifting during the middle Mesozoic saw the opening of the present North Atlantic Ocean. In the Montreal area this event is represented by the Saint Lawrence rift system, a series of tensional faults aligned with the older fault zones associated with the Ottawa-Bonechere and Saint Lawrence grabens (Kumarapeli and Saull, 1966; Kumarapeli, 1978). The event also reactivated deep-seated faults extending eastward from the Ottawa-Bonnechere graben across the Appalachian tectonic terranes. These are believed to have provided conduits for the emplacement of the Monteregian Hills igneous intrusions of Cretaceous age.
The most prominent topographical feature on the Island of Montreal is Mont Royal (Mons Regius in Latin), the type pluton which gave the Monteregian Hills alkaline igneous province its name (Adams, 1903). The Monteregian Province comprises an east-southeast-trending belt of ten major plutons, and numerous dikes, sills, small plugs and diatreme breccia pipes (Currie, 1976). Their ages range from 107 to 140 million years (Eby, 1987).
The major intrusions include the Oka carbonatite complex (32 km west of Montreal) which intrudes Proterozoic rocks of the Grenville Province; the major plutons Mont Royal, Mont Saint-Bruno, Mont Saint-Hilaire, Rougemont, and Mont Saint-Gregoire, which intrude the Saint-Lawrence Platform; Mont Yamaska at the western edge of the Humber Zone; and Mont Brome, Mont Shefford, and part of Mont Megantic, in the Appalachian Province. The major intrusions are all zoned, reflecting successive pulses of magma of varying composition and age. They also show a marked change in their overall composition from east to west, becoming progressively more mafic, with a tendency toward agpaicity in late differentiates.
Dikes and sills are more numerous in the western end of the Monteregian Province, and are especially abundant in the Montreal area. They include the Saint-Michel sills and dikes, exposed in the Francon quarry; the sills and dikes in the former Miron quarry (Pare, 1972; Sabina, 1978); the Saint-Amable sill (Clark, 1955; Globensky, 1985; Horvath et al., 1998); the Montreal-Est sills and dikes in the Lafarge (Montreal-Est) quarry; the now-buried Masson Street sill (Adams, 1913; Clark, 1952); the Sainte-Dorothee sill (Howard, 1922: Clark, 1952); the l'Ephiphanie sill (Clark and Globensky, 1977); the Saint-Luc sill (Clark, 1955; Globensky, 1985); and the now-buried Longueuil (Polis quarry) sill (Clark, 1955).
GEOLOGY OF THE FRANCON QUARRY
Exposed in the Francon quarry are about 80 meters of Ordovician-age limestone and interbedded sills. Only the upper 38 meters, on the first level at the southeast end, have been examined in detail (Clark, 1952). The limestone beds in this section are assigned to the Saint-Michel Member of the Montreal Formation of the Trenton Group. Underlying these are Mile End Member limestones, also belonging to the Montreal Formation. Based on the sedimentary succession determined elsewhere in the Montreal area (Clark, 1972), a thickness of about 4 meters can be assigned to the Mile End Member. Below the Trenton Group limestones are about 15 meters of strata comprising the Black River Group. This group includes beds of dolomite and shale in the lowest 2.5 meters. Below the Black River Group and down to the bottom of the quarry are Chazy Group limestones. The quarry is located on the flank of a very shallow anticline with the limestone beds dipping a few degrees to the northwest. In some places the beds are cut by normal faults which have resulted in vertical displacements of up to 2 meters. These faults are related to regional tectonism during the Mesozoic (Rocher and Tremblay, 2003).
Although the Saint-Michel carbonatized phonolite sills are the best known feature of the Francon quarry, other sills and dikes are exposed throughout the quarry. Clark (1952) recorded four sills of "basic rock" from 8 cm to just over 1 meter in thickness intruding the Saint-Michel Member beds on the first level. Other sills and dikes, some up to 1.5 meters thick, occur in the lower levels of the quarry. Some of these cut the Saint-Michel sills. They consist of a variety of fine-grained to coarse-grained, often porphyritic, rocks most of which weather to a brown color. In the Montreal area such rocks are mostly alkaline syenite, monzonite, basanite or alkali olivine basalt, and lamprophyre, especially camptonite (Hodgson, 1968; Eby, 1985).
A major lamprophyre sill, over 3 meters thick, is exposed in the nearby Miron limestone quarry (Pare, 1972). A common feature of the lamprophyres noted by Hodgson (1968) is the formation of loose spheroids on weathered surfaces caused by the presence of coarse-grained, feldspar-rich ocelli [= eyes in Latin] which are more weather-resistant than the finer-grained matrix. This phenomenon is observed in some of the Francon quarry dikes.
As part of the present study, rock from two different dikes in the Francon quarry was examined in thin section. A very fine-grained rock from one dike was interpreted to be a nepheline microsyenite or micromonzosyenite, and a medium-grained, porphyritic rock was classified as a camptonite (D. Dolejs, personal communication, 2004). Roberts et al. (1990) have described one of the dike rocks in the alcove in the quarry as an "altered amygdaloidal basalt." Some of the minor sills in the alcove also appear to be basaltic.
The Saint-Michel Sills
Three major sills, exposed in the Francon quarry, are collectively referred to as the Saint-Michel sills: the weloganite-bearing upper and lower sills, exposed on the second and third levels, respectively, and a third sill that was exposed at the bottom of the third level. Very little information has been recorded about this now-inaccessible third sill.
Petrology and Chemistry
The upper Saint-Michel sill has an average thickness of about 2 meters, thinning from about 2.5 meters in the southeast to 1.2 meters in the northwest (Steacy and Jambor, 1969). It can be traced around the entire perimeter of the quarry, which covers an area of about 0.7 [km.sup.2]. Exposures in the quarry walls and exploratory drill holes indicate that the sill extends in all directions beyond the present quarry limits. However, it does not appear in the currently exposed section of the southeast wall in the nearby Miron quarry, which is only 750 meters southwest of the Francon quarry.
The sill is not a continuous horizontal sheet. In places the sill wedges out and reappears at a different stratigraphic horizon. In other places its emplacement changes abruptly, by up to about 10 meters, from one horizon to another. Sections of the sill have also been faulted, with displacements of several meters.
Steacy and Jambor (1969), Jambor et al. (1976), and Simpson (1980) have provided descriptions of the petrology and chemistry of the upper sill. The sill rock is dense, fine-grained, and predominantly pale gray, with darker gray blebs. Locally, it contains mineral-filled amygdules less than 1 cm in diameter. In some areas near its contact with limestone the sill rock has a coarsely mottled texture consisting of dark gray circular patches several centimeters across with pale gray rims set in a medium gray matrix. The contact between the sill and the limestone is sharp, with a thin (about 5 cm) chill zone that varies from greenish gray to dark green and brown. The limestone at the contact shows some discoloration and very minor recrystallization. In a few places, minor brecciation has occurred at the contact.
No detailed investigations have been carried out on the lower sill. It has an average thickness similar to the upper sill, and is also exposed around the entire perimeter of the quarry. The rock in the lower sill is a predominantly greenish gray to pale greenish brown color. Based on a visual examination of samples of the lower sill, Jambor et al. (1976) concluded that the upper and lower sills are "similar" and "unquestionably related, and likely derived from a common feeder." The most striking feature of both the upper and lower sills are the numerous, crystal-lined miarolitic cavities which constitute up to several percent of the volume of the sills. These are concentrated in the center to the upper quarter of the sills.
Petrologically, the sills are unique in being carbonate-rich with dawsonite as the main carbonate mineral (Jambor et al., 1976). In thin sections, samples representative of the bulk of the upper sill show phenocrysts up to about 2.5 mm in maximum dimension, in a groundmass with a trachytic texture. The main constituents are dawsonite and fine laths of orthoclase, with minor dolomite and siderite. In some parts of the sill the groundmass contains fine needles of aegirine-augite. Other accessory minerals identified in the groundmass are albite, anatase, apatite group, calcite, magnetite, marcasite, perovskite, pyrite, pyrochlore, quartz, weloganite and zircon (Jambor et al., 1976; Simpson, 1980). The phenocrysts are predominantly dawsonite pseudomorphs after analcime. Minor amounts of unaltered phenocrysts of analcime and lath-like phenocrysts of albite are also present. Some dawsonite has been observed to fill microfractures which cut across both the albite phenocrysts and the groundmass (Stevenson and Stevenson, 1977). No modal analyses of the sill rock are available. The color of the sill rock in the mottled zones near the contacts correlates with variations in the relative proportion of minerals in the groundmass: darker gray areas contain more carbonates whereas paler gray areas contain more orthoclase. The presence of aegirine-augite imparts a greenish color to the rock.
Whole-rock chemical analyses of the upper sill have been reported by Steacy and Jambor (1969), Jambor et al. (1976), and Simpson (1980). Steacy and Jambor investigated the horizontal distribution of zirconium, niobium and strontium in the sill by collecting and analyzing single-point samples around its entire perimeter. A selection of these samples representative of different parts of the sill was submitted to a full analysis by Jambor et al. Their analyses are reproduced in Table 1, together with averages of the zirconium, niobium and strontium concentrations measured by Steacy and Jambor. Simpson, who sampled the sill across its thickness at two locations, reported similar whole-rock analyses. A compositional profile across the sill at one of the locations is shown in Fig. 8. The results of all three studies demonstrate that the chemical composition of the sill is fairly uniform. Also included in Table 1 are calculated (Na + K)/Al molecular ratios. These indicate that the sill rock is marginally agpaitic (i.e. (Na + K)/Al = 1). Of the complex silicates of Zr, Nb and Ti that normally characterize agpaitic rocks, only minor amounts of elpidite are present. They are replaced by carbonates and oxides of these elements, including weloganite, franconite, sabinaite and hochelagaite.
Based on its relatively high carbonate content, Jambor et al. (1976) classified the sill rock as a "silicocarbonatite" but noted that one of their samples (E in Table 1) approached an alkali syenite in composition and mineralogy. However, the sill rock does not meet the more widely accepted definition of a carbonatite as being a magmatic rock containing more than 50 percent by volume of carbonate minerals (Heinrich, 1966; Le Maitre et al., 1989). On the basis of the chemical composition and relict primary mineralogy, Vard and Williams-Jones (1993) concluded that the sill rocks are more appropriately classified as altered agpaitic phonolites.
The origin and age of the Saint-Michel sills have not been investigated. (2) Grice (1989) speculated that the sills and Mont Royal had a common magmatic source. However, in an investigation of the trace-element chemistry and age of four mafic alkaline dikes in and around Mont Royal, Eby (1985, 1987) concluded that the dikes represent two episodes of igneous activity and emanated from a different magma source than the main Mont Royal intrusive mass. Their ages fell within two distinct intervals: 139 to 129 million years, and 121 to 117 million years. Since the Saint-Michel sills are cut by similar mafic alkaline dikes, Eby's data suggest that they have a minimum age of 117 million years. In the absence of trace-element chemistry, the relationship of the sills to the Mont Royal intrusion, if any, and the nature and source of the magma remain unknown.
Genesis of the Sill Rock and Mineralized Cavities
The fact that the Saint-Michel sills and their mineral assemblages are unique not only in the Monteregian province but worldwide, suggests that they formed under very unusual conditions. Fluid inclusions in the cavity minerals can provide some insight into the fluid composition, temperature and pressure that prevailed when the minerals crystallized.
Vard and Williams-Jones (1993) investigated the fluid inclusions in quartz, calcite and weloganite. The inclusions were found to variously contain a saline (NaCl) solution, a carbonic (C[O.sub.2]) phase, and a solid phase (nahcolite, dawsonite or weloganite). Analyses of the salt residue from decrepitated inclusions showed a relatively high concentration of aluminum and sulfur in addition to sodium and chlorine. Microthermometric measurements on the inclusions indicated that quartz, calcite and possibly weloganite in the sill cavities crystallized at temperatures between 360[degrees] and 400[degrees]C at a pressure of 450 bars. Dawsonite and probably some of the other minerals crystallized at temperatures between 250[degrees] and 300[degrees]C, and nahcolite crystallized at temperatures below 120[degrees]C.
Jambor et al. (1976) and Vard and Williams-Jones (1993) have proposed similar models for the evolution of the phonolite immediately prior to or after it was intruded. As it cooled, the partially crystallized phonolite magma, consisting largely of phenocrysts of analcime and albite in a potassium-rich melt, exsolved a hydrous fluid charged with C[O.sub.2]. As the fluid degassed, cavities were formed in the solidifying magma. Sodium, aluminum, chlorine, fluorine, sulfur and incompatible elements such as barium, strontium, zirconium, niobium and titanium partitioned into an aqueous phase. With a decrease in temperature, weloganite and other cavity minerals were precipitated from the saturated solution. Emplacement of the magma into the relatively cold limestone resulted in chilled margins that effectively sealed the fluids within the cooling magma under a relatively high lithostatic pressure. This promoted diffusion and infiltration of the fluids throughout the solidifying magma, causing pervasive late-stage alteration of analcime and other primary minerals to dawsonite. The alteration of analcime to dawsonite probably proceeded according to the reaction:
Na[Al[Si.sub.2][O.sub.6]*[H.sub.2]O + C[O.sub.2] = NaAl(C[O.sub.3])(OH)[.sub.2] + 2Si[O.sub.2]
Vard and Williams-Jones likened the autohydrothermal processes in the sills to the phonolite having "stewed in its own juices." Local variations in temperature and solution chemistry resulted in a highly variable mineral assemblage and an often complex mineral paragenesis in the sill cavities, with crystallization of some minerals in two episodes.
Dawsonite of hydrothermal origin occurs in other dikes and sills in the Montreal area. At the type locality on the McGill University campus, dawsonite is found along joints and as disseminated clusters in a feldspathic dike (Stevenson and Stevenson, 1965). Dawsonite has also been observed as a cavity mineral in feldspathic dikes about 1 km south of the McGill campus (Stevenson and Stevenson, 1977), and at Mont Saint-Bruno (Stevenson and Stevenson, 1978). In the phonolite sill at Saint-Amable, dawsonite is restricted to the hydrothermally altered contact zone and the rare hydrothermal pods (Horvath et al., 1998). Dawsonite has also been found very sparingly in a lamprophyric sill in the Miron quarry (Sabina, 1978) and in the Lafarge Carriere Montreal-Est quarry. The latter sill is also the second of three known weloganite localities but here the mineral is extremely rare. Significantly, none of these occurrences contains a mineral assemblage comparable to that of the Saint-Michel sills, and petrographically they are all different, underlining the uniqueness of the Saint-Michel phonolite sills.
MINERALIZATION
The well-crystallized and rare species for which the Francon quarry is celebrated occur almost exclusively in cavities in the phonolite sills. A small but important suite of minerals is also found in some of the dikes and other sills, and a few common species are encountered in the limestone host rock.
Phonolite Sills
The sill minerals occur in miarolitic cavities, embedded in the sill rock, and in mineral-filled fractures extending into the surrounding limestone.
Miarolitic Cavities
The miarolitic cavities range in size from a few millimeters to more than 30 cm in maximum dimension. Most are in the 5-10 cm range. They vary in shape, from spherical to oblong, lenticular and irregular. Larger cavities are elongated and flattened in the plane of the sills. Often a series of cavities is strung out in groups aligned parallel to the sill contacts. The abundance of the cavities varies in different parts of the sill, and locally they may be almost absent.
An interesting phenomenon sometimes observed, when sill rock is broken up, is the sudden appearance of fluids seeping from newly exposed cavities. Although the fluids probably represent trapped meteoric water, they may also contain components derived from the original hydrothermal fluids. This would account for the occurrence of halite and nahcolite as patches on the surface of sill rock.
There are notable differences in the suite of minerals found in the upper and in the lower sills. Sabina (1979) denoted the minerals in the upper sill as "assemblage A." This assemblage consists of albite, quartz, dawsonite, weloganite and calcite as the principal minerals, with less abundant strontianite, barite, cryolite, fluorite and pyrite. The mineral assemblage in the lower sill, denoted as "assemblage B," consists predominantly of calcite, dawsonite, weloganite, fluorite, quartz, analcime and albite, with fairly abundant strontianite, celestine, barite, montmorillonite, marcasite and hematite. Of the new species first described from the Francon quarry, only weloganite and doyleite are found in both sills, whereas the occurrence of dresserite, hydrodresserite, strontio-dresserite, sabinaite and montroyalite is confined to the upper sill. Table 2 lists all the minerals known to occur in the cavities, with an estimate of their relative abundance.
Within the sills, the cavity mineralization is highly variable. The cavities are most commonly lined with crystals of one or more of the following species: quartz, calcite, albite, dawsonite and analcime. Crystals of many other species occur implanted on the cavity linings, following a rather well-defined paragenetic sequence. Some cavities afford clean crystals, whereas in other cavities the crystals are commonly coated or crusted over. Several of the type minerals from the Francon quarry form at least part of these coatings and crusts. Late-stage dissolution and replacement of cavity minerals is also commonly observed.
Certain mineral associations are common and repeatedly found in the cavities. Others have been found on only one or a few occasions.
Fig. 12 summarizes the observed paragenetic sequence of mineralization in the sill cavities for the more common species. Because of the highly variable and sometimes complex cavity mineralization, there is some uncertainty in the paragenetic relationship among some of the species shown, particularly for the lower sill. Nevertheless, fairly consistent trends are observed in the emplacement of minerals which occur in both sills. A notable feature of many cavities is the presence of two generations of the most common minerals.
Sill Rock Minerals
A number of mineral species are found only in the sill rock. Those occurring as embedded euhedral to anhedral grains, such as apatite, are essentially accessory minerals which are distinguishable because of their size (up to 1 mm) in relation to the fine-grained matrix. The sill rock commonly has a spotted appearance due to the segregation of rock-forming and other minerals into blebs or patches a few millimeters across.
More conspicuous are amygdule-like mineral-filled cavities up to a centimeter in size. They usually contain white carbonate minerals and stand out in contrast to the darker matrix. They tend to be flattened and elongated parallel to the sill contacts. Locally, they can be quite abundant, especially in the lower sill.
Mineralized Fractures
Very rarely encountered are mineralized fractures extending from the sills into the host limestone. Simpson (1980) noted an area below the lower sill where the limestone had been altered by hydrothermal solutions penetrating joint planes. One of the present authors (PT) observed an open fracture containing well-crystallized dawsonite with strontianite and calcite. Chamberlain and Doell (1982) reported similar occurrences of dawsonite, and of strontianite associated with celestine.
Dikes and Minor Sills
With a few notable exceptions, most of the dikes and minor sills in the quarry contain little of real interest to mineral collectors. The new species voggite (Roberts et al., 1990), a sodium-zirconium phosphate-carbonate, was discovered in a dike cutting the upper phonolite sill, and was postulated to have formed by reaction between the intruding dike magma and the zirconium-rich sill. A garronite-like zeolite mineral, a potentially new species, has been found in one of the minor sills.
Conspicuous in some of the porphyritic dikes are large phenocrysts of various ferromagnesian minerals.
Limestone Host Rock
Mineralization in the limestone formations exposed in the Francon quarry is limited to occasional small cavities, veins and solid pods containing common minerals such as calcite, dolomite, strontianite, barite, quartz, pyrite and marcasite. (3)
MINERALOGY
The mineralogy of the Saint-Michel sills in the Francon quarry is unique, not only in the Monteregian Hills alkaline igneous province but also globally. Although some of the type minerals--weloganite, doyleite, franconite, sabinaite, strontiodresserite and hochelagaite--have been found elsewhere, most notably in two other Monteregian province localities (Mont Saint-Hilaire and Saint-Amable), others like dresserite, hydrodresserite, montroyalite and voggite remain unique to the Francon quarry. The abundance of well-crystallized dawsonite in itself makes the quarry an important locality on a worldwide scale. Including what are essentially rock-forming minerals, a total of 90 mineral species have been reported from the quarry (Table 3). They include two native elements, eight sulfides, 18 oxides, 8 sulfates, three halides, 18 carbonates, three phosphates, 28 silicates and two organic minerals.
For the mineral collector, the task of identifying Francon minerals using visual characteristics and simple chemical tests ranges from very easy for such species as weloganite, dawsonite, calcite, quartz and some cryolite, to very difficult or impossible for such species as franconite, hochelagaite, doyleite, sabinaite and montroyalite, which are all white and occur as tiny globules, coatings and encrustations, often as a mixture of two or more species. Minerals in the latter category require instrumental analysis for proper identification, at least X-ray diffraction analysis, and the results can only be applied to the specimen analyzed or at best to identical specimens from a particular cavity. For some minerals the response to ultraviolet radiation (see below) can be helpful in their identification. Certain associations of minerals in which one species is an indicator of the possible presence of another, e.g. hematite and baddeleyite, can also be helpful (Sabina, 1979; Cares, 1993). Various aids to identification have been noted in the mineral descriptions which follow.
Unknown and Undetermined Minerals
From the beginning of her investigation of the Francon quarry minerals, Ann P. Sabina (APS) of the Geological Survey of Canada (GSC), applied consecutive numbers to minerals that instrumental analysis suggested were "unknowns" and possible new species (Sabina, 1976, 1979, 1994). In the mineral descriptions below these appear as APS Nos. 1-15. Although the minerals have now all been identified, the numbers are still worth remembering because they appear in various earlier mineral lists and publications.
A number of minerals reported from the locality have not been fully characterized, either as to species within a group, or within a series. In most cases these will require a full chemical analysis, and for some minerals there is currently insufficient material available.
Type Minerals
To date, the Francon quarry is the type locality, or the co-type-locality with Mont Saint-Hilaire, for ten new mineral species. These are listed in Table 4 in chronological order of their description.
Fluorescent Minerals
A number of Francon quarry minerals are fluorescent and/or phosphorescent in response to ultraviolet radiation. Table 5 details the responses observed under shortwave, medium-wave and longwave ultraviolet radiation. Where different specimens of the same species have given different responses, they are listed separately. It should be noted that the responses given here may differ from those reported elsewhere because of the particular specimens investigated or the particular ultraviolet wavelength and power level employed. The equipment used in the present study was manufactured by WTC (Way Too Cool) Inc. The wavelength specifications were 254 nm for shortwave, 312 nm for medium-wave, and 352 and 368 nm (combined in Table 5) for longwave. The ultraviolet radiation sources were rated at 8 W (watts) for the short and medium wavelengths, and 18 W for the 352-nm longwave lamp.
Mineral Descriptions
The following mineral descriptions are based on published descriptions, especially those of Sabina (1976, 1979) and the various papers describing the new species and other minerals from the Francon quarry, on unpublished material provided to the authors, and on the authors' collecting records and the examinations of many hundreds of specimens in private and institutional collections. With a few exceptions, the authors have examined confirmed specimens of all the species described. In the course of this study, several minerals not previously reported from the Francon quarry were identified. A large proportion of the studied specimens are in the collection of the authors, assembled beginning in 1968 but especially during an intense period of collecting in 1973-1980 when the quarry was most active. Most of the very rare and unusual species were examined in the special Francon quarry study collection of analyzed and documented mineral specimens assembled by Sabina and now deposited in the Reference Series of the National Mineral Collection housed at the GSC in Ottawa. Some of these specimens have been referenced in the mineral descriptions with a specimen number and the prefix GSC APS. Other Francon quarry specimens were examined in the Display Series of the National Mineral Collection housed at the Canadian Museum of Nature, Gatineau, Quebec, and in the collections of the Redpath Museum, McGill University, Montreal, and Donald V. Doell of Grafton, Ontario.
Mineralogists from several institutions participated in the characterization and description of the new mineral species from the Francon quarry. Taking a lead role were Sabina and her colleagues at the GSC, especially J. L. Jambor, later with the Canada Centre for Mineral and Energy Technology (CANMET), and A. C. Roberts. Also contributing to the description of the new species were mineralogists from the Royal Ontario Museum, Carleton University, CANMET, and the Canadian Museum of Nature. Their work is referenced throughout. Most of the identifications of the other species described here were also made at the GSC, notably by A. C. Roberts (X-ray diffraction analysis). Other mineral identification work was carried out by G. Y. Chao of Carleton University, Ottawa, and R. A. Gault and R. Rowe of the Canadian Museum of Nature, Gatineau.
MINERALS
Aegirine Na[Fe.sup.3+][Si.sub.2][O.sub.6]
Aegirine is a relatively rare cavity mineral in the lower sill, found most commonly in the north corner of the quarry. It occurs as vitreous, transparent, typically bicolored, very sharp, thin bladed crystals, 1-3 mm long. The color grades from pale olive-green in the center of the blades to pale brown at the edges. Aegirine is paragenetically one of the earliest minerals in the cavities, and is associated with analcime (usually as a cavity lining), ankerite, dolomite, quartz (mostly etched crystals), siderite, albite, weloganite, fluorite and, rarely, tiny rosettes of brookite. In some earlier lists of Francon quarry minerals, aegirine is listed as clinopyroxene or acmite.
Albite NaAl[Si.sub.3][O.sub.8]
Albite is very common as a drusy cavity lining in both the upper and lower sills. It occurs as vitreous to dull, colorless to opaque white plates up to 3 mm long. The plates consist of individual crystals stacked along [010] with sharply pointed terminations extending from the plates, producing a serrated edge. Some of the colorless plates show a peculiar faden-like effect. Associated minerals include nearly all the cavity minerals. Albite is listed as plagioclase in some earlier publications.
Almandine [Fe.sub.3.sup.2+][Al.sub.2](Si[O.sub.4])[.sub.3]
Reported by Sabina (1979) as a rare accessory mineral in the sill rock, almandine occurs as pale pinkish, granular aggregates, admixed with gray quartz, in patches up to 1.5 cm in diameter. Visually distinct almandine aggregates are up to 3 mm in diameter. Massive dawsonite is associated with the almandine-quartz patches.
Amphibole group
Amphiboles are common rock-forming minerals in some of the dike rocks in the quarry and may be visible as phenocrysts. A clinoamphibole has been identified by X-ray diffraction as brown laths in a dike in the alcove, and also as black grains and patches in sill rock (Sabina, personal communication, 2004). A chemical analysis would be required to determine the specific member(s) of the amphibole group present.
Analcime Na[Al[Si.sub.2][O.sub.6]]*[H.sub.2]O
A common species in the lower sill, and rarer in the upper sill, analcime occurs as transparent to translucent to opaque, colorless, white, pale brown, yellow brown, orange and pale green crystals with a vitreous to waxy to dull luster. The crystals range in size from a few millimeters to nearly 1 cm in diameter. The predominant form is the {211} trapezohedron, often modified by small cube faces. However, cubic crystals with dominant {100} modified by {211} are not uncommon. In the lower sill, analcime crystals commonly occur as a drusy cavity lining, commonly in parallel growth, and as globular aggregates of colorless to pale brown crystals. Analcime has also been identified as powdery and porcelaneous aggregates, as thin shells of crystals from which most of the mineral has been leached out (Sabina, 1979), and as small crystalline masses in the sill rock. Chamberlain and Doell (1982) have reported the occurrence of analcime pseudomorphs after an unidentified orthorhombic mineral in the lower sill. Analcime is one of the earliest minerals in both the upper and lower sill cavities. It is commonly found completely overgrown by later species such as fluorite, dawsonite and ankerite. Associated minerals include nearly all the cavity minerals.
Analcime has also been found in cavities in a dike in the alcove as hemispherical intergrowths of colorless trapezohedra, and as opaque white cubes modified by small trapezohedral faces, less than 1 mm in size. Associated minerals include dolomite, mordenite, cristobalite and synchysite-(Ce). In other dike occurrences, crystals of analcime colored red by unidentified inclusions line calcitefilled fractures; a cavity lined by analcime crystals was found filled by aggregates of sharp, colorless to pale yellowish gypsum crystals and thin, bladed strontianite crystals.
Anatase Ti[O.sub.2]
Anatase has been identified in sill cavities as tan, powdery coatings, and as gray, submetallic, flaky aggregates associated with siderite and ilmenorutile. It also occurs in the sill rock as embedded, pale brown, flaky aggregates less than 0.5 mm across. It is very rare, and visual identification is unreliable.
Ankerite Ca([Fe.sup.2+],Mg,Mn)(C[O.sub.3])[.sub.2]
A very common mineral in the lower sill, ankerite occurs as aggregates of transparent to translucent, predominantly yellow and less commonly beige, greenish yellow, and pale brownish yellow rhombohedra, 1-2 mm in diameter, with a vitreous luster. Some of the crystals appear rounded due to the presence of indistinct second-order rhombohedrons as modifying faces. Mosaic-like growth features are observed on some faces. Ankerite has also been found as spherical aggregates of yellow prismatic crystals; white tabular crystals forming rosettes and curved stacked aggregates; white fibers forming spheres; and yellowish green fibrous and granular masses.
Ankerite is an early to late-stage mineral in the cavities. It is often closely associated with siderite, and is commonly observed in cavities containing a dawsonite-celestine-goethite-hematite assemblage. Other associated minerals include calcite, dolomite, analcime, fluorite and weloganite, and very rarely also baddeleyite, dachiardite-Na, mordenite and bastnasite. Sight identification of ankerite is not reliable because the associated dolomite and siderite can be quite similar in morphology and physical appearance. Because ankerite forms a solid solution series with dolomite. determining which species is present can be problematic even with X-ray diffraction analysis. For this reason, ankerite appears in some Francon quarry species lists as "dolomite-ankerite series" (Sabina, 1976).
Apatite group [Ca.sub.5](P[O.sub.4])[.sub.3]F
An apatite group mineral, most likely fluorapatite, was reported to occur in sill rock as "euhedral to anhedral grains of apatite averaging about 0.04 mm" (Jambor et al., 1976), and as "smoky transparent grains" (Sabina, 1979). Colorless grains, and colorless, well-formed, hexagonal prisms up to 3 mm have been observed embedded in dike rock containing phenocrysts of an undetermined amphibole group mineral.
Baddeleyite Zr[O.sub.2]
The Francon quarry is the second known locality for baddeleyite in Canada. It is a very rare species in cavities in the lower sill at the north end of the quarry, and at least one specimen is known from the upper sill (alcove section). Baddeleyite occurs as vitreous to waxy, tan, pale, yellow and yellowish brown, scaly, finely granular, powdery, lamellar and cellular aggregates up to 1 cm across. The aggregates consist of minute spheres, 5-10 [micro]m in diameter. The relict nature of the aggregates, which can form pseudomorphous lamellae, within thin outer shells having the morphology of welcoganite (sometimes retaining the characteristic striations of welcoganite), suggests that the baddeleyite was derived from the hydrothermal alteration of welcogtanite. Further evidence of this is seen in the deposition of powdery baddeleyite on the laminar remnants (parallel to {001}) of partially dissolved crystals of weloganite. For this reason the baddeleyite lamellae are preferentially aligned parallel to the {001} pedion of the replaced weloganite crystals. In some specimens haddeleyite is intimately intergrown with grains of zircon (Sabina, 1979).
Baddeleyite is an intermediate to late-stage mineral. Associated minerals include hematite, dawsonite, quartz, calcite, kaolinite, barite, fluorite, ankerite, celestine, rarely weloganite and very rarely paratacamite. Most specimens of baddeleyite were collected in 1975 from cavities very rich in reddish brown globular and powdery hematite that partially (sometimes selectively) coats the cavity minerals. The presence of hematite is a useful indicator of the potential presence of baddeleyite.
Barite BaS[O.sub.4]
Barite is one of the more common cavity minerals that have provided attractive crystallized specimens. It occurs as well-formed crystals of various habits mostly in the lower sill. Barite is uncommon in the upper sill cavities, and rare in small cavities in the limestone near the sill contacts. It is abundant throughout the lower sill, with noted local concentration near the northwestern wall, where some of the largest, exceptionally well-formed crystals were found in 1975. Barite occurs as colorless, pale yellow, pink, white and gray, prismatic to columnar, thick tabular to think platy single crystals; as aggregates of platy crystals; as granular to powdery masses; and as spheroids, sheets, and slivers. The following crystal habits and morphologies have been observed, practically all in specimens from the lower sill.
Habit A consists of thick tabular crystals, flattened on (001) and elongated on [100]. The crystals are defined by dominant {001} basal pinacoids and prominent {011} prisms, terminated by {101} and {210} prisms, and often modified by minor {012} prism and {212} pyramid. Crystals of this habit and the large crystals of habit C were found exclusively in 1975. The crystals are 1-3 cm long, rarely up to 4.5 cm, and sometimes doubly terminated. The {001} pinacoid faces are translucent and frosty whereas the {011} and most other prisms have a thick, opaque white, pitted, glaze-like layer with a satiny luster; the crystals are transparent, pale yellow internally.
Habit B is characterized by columnar or prismatic crystals in which the {011} prism is prominent and often dominant. This is the most common habit, with crystals ranging from 1 mm to about 2.5 cm in length. The small crystals can be morphologically quite simple, typically defined by the dominant {011} prism and terminated by the {101} prism, with or without a small {100} pinacoid. The small crystals may be colorless to transparent, pale yellow or (rarely) pale pink. The larger columnar crystals are similar to the thick, tabular crystals of habit A, except for the smaller {001} basal pinacoid, giving the crystals a nearly hexagonal cross-section.
Habit C consists of thin, tabular and platy crystals, with the same forms as habit A, but even more dominant {001} pinacoids, all other forms being minor. Nearly all the crystals are colorless, but those in the upper sill commonly have a thin, opaque white outer zone with a silky luster. The crystals range in size from 1 to 6 mm. This is a relatively rare habit.
Habit D crystals are tapering, bladed, often rounded, and sometimes twisted, forming sheaves, spheres, rosette-like and stacked aggregates up to 6 mm in diameter. The crystals are invariably opaque and may be white, pale yellow, orange-red or dark red. The reddish color is imparted by varying amounts of hematite inclusions and coatings.
The most commonly associated minerals include weloganite, cryolite, strontianite, dawsonite, celestine, elpidite, marcasite, gibbsite, quartz, hematite, goethite, siderite, fluorite, analcime, albite, baddeleyite and calcite.
Bastnasite-Hydroxylbastnasite series
Bastnasite, probably bastnasite-(Ce), occurs in the lower sill as dull to chalky white, compact spherules less than 1 mm in diameter associated with ankerite, dawsonite, strontianite, quartz and fluorite, and as silky, tan spherules on ankerite and quartz (A. P. Sabina, personal communication, 2004). A chemical analysis would be needed to determine the exact species.
Biotite series
Jambor et al. (1976) reported "rare relict phenocrysts of biotitephlogopite" in very minor quantities in the upper sill rock. Sabina (1994) also reported "mica-biotite, phlogopite associated with APS No. 9 (= dachiardite-Na)" in the lower sill. A yellow-brown mica has been observed as flakes less than 1 mm in diameter embedded in a dike rock from the alcove. No chemical analyses have been carried out on these micas.
Brookite Ti[O.sub.2]
Brookite is a relatively rare mineral at the Francon quarry, typically found on cavity linings of white albite crystals, in both the upper and lower sills. It occurs as dull black, sub-metallic rosettes, about 1 mm in diameter, consisting of thin plates with a roughly hexagonal outline, and a rough, furrowed surface. Brookite is often coated by a black crust that has been identified in some specimens as ilmenorutile (Sabina, 1979), and may be the reason for the surface roughness. Other associated minerals include dawsonite, barite, elpidite, natrolite and quartz. Visual identification of brookite is unreliable inasmuch as ilmenorutile has also been observed to occur as black rosettes.
Calcite CaC[O.sub.3]
Calcite is a ubiquitous cavity mineral in the upper and lower sills. It occurs as colorless, translucent to transparent, pale yellow, white or beige crystals, and as opaque, white and brown crystals 1-10 mm long. Some crystals are a mottled gray color due to inclusions. The majority of the crystals are either scalenohedral or rhombohedral. The dominant form on the scalenohedral crystals is {21[bar.3]1}, usually terminated by a {10[bar.1]1} rhombohedron, and rarely a {0001} pinacoid. Crystals with acute terminations ("dogtooth" calcite) are uncommon, as are crystals showing the prismatic {10[bar.1]0} form. Rhombohedral crystals are predominantly simple {10[bar.1]1} rhombohedrons, sometimes with small faces of a negative rhombohedron. Twinning has not been observed. Scalenohedral crystals often have a frosty appearance, with a dull to greasy luster, and many are rounded, or barrel-shaped. Aggregates of crystals in parallel growth are also observed. Rhombohedral crystals tend to be sharper and more lustrous. In an unusual occurrence, calcite has been found as sharp pseudomorphs to 1 cm after an unknown precursor mineral; the crystals have a chalky-white exterior and colorless interior, and an apparently triclinic symmetry.
Calcite commonly occurs as an early mineral in the cavity linings, but quite often a second, late-stage generation of calcite is found in the same cavity. Calcite is associated with practically all the minerals found in the quarry, and it is often found selectively coated by other minerals. Perimorphs after calcite consisting of thin, dull white shells of gibbsite, fluorite and rarely doyleite, have been observed. Some calcite fluoresces very bright red, and sometimes an unusually vivid and intense pink under shortwave and medium-wave ultraviolet radiation. The fluorescence can help to distinguish rhombohedral crystals of calcite from similar-appearing dolomite.
Calcite is also found as small crystalline masses in the sill rock, and as well-formed, colorless crystals in cavities in dikes and in the limestone host rock.
Celestine SrS[O.sub.4]
Celestine is found in both the upper and lower sills, but it is far more abundant in the cavities in the lower sill. It occurs as sharp, colorless, white, yellow and pale blue tabular and prismatic crystals up to 2 cm long, and more commonly as attractive bundles, sheaves and divergent sprays up to 3 cm long, consisting of colorless, and translucent to opaque, white to pink, long prismatic and acicular crystals. Tabular crystals show the following forms, in descending order of dominance: {001} and {010} pinacoids, {101} and {011} prisms, and small {322} dipyramids. Prismatic crystals show major {001} and minor {010} pinacoids, prominent {011} and {012} prisms, terminated by {21l} dipyramids (usually etched). Some bladed prismatic crystals have serrated edges caused by reentrant angles formed by opposing faces of {21l} prisms.
Celestine has also been found in at least one dike cavity as colorless, very thin, bladed crystals associated with gypsum and analcime. In the presence of hematite, celestine crystals commonly are colored reddish brown or black by hematite inclusions, and in the presence of goethite they are often found coated by a velvety, golden yellow layer of fibrous goethite. The hematite and especially goethite have a marked tendency to selectively coat celestine, but not other associated minerals in the same cavities.
Cerussite PbC[O.sub.3]
Cerussite is an extremely rare, late-stage alteration product, occurring as white powdery coatings or tan crusts, sometimes admixed with hydrocerussite, on galena crystals in the lower sill.
Chromite [Fe.sup.2+][Cr.sub.2][O.sub.4]
Chromite has been identified as black grains in a dike in the alcove (A. P. Sabina, personal communication, 2004).
Cristobalite Si[O.sub.2]
Cristobalite is a relatively rare accessory in the lower sill cavities, occurring as dull, opaque, white to bluish, rounded and platy aggregates 1-2 mm across, associated with quartz, ankerite, celestine, mordenite and baddeleyite, and as compact, white, matted, fibrous masses up to 3 mm across, associated with calcite, dolomite, pyrite and marcasite (Sabina, 1979). Cristobalite has also been found in cavities in a dike in the alcove as white to pale bluish globules less than 1 mm in diameter, associated with analcime, dolomite, strontianite and mordenite.
Crocoite PbCr[O.sub.4]
Crocoite has been identified as "yellow, waxy patches in microcrystalline intergrowths of dawsonite and "K-feldspar" which also contain pyrochlore, pseudorutile and siderite" (Sabina, 1979). Only one confirmed specimen, from the lower sill, is known (GSC APS 264).
Cryolite [Na.sub.3]Al[F.sub.6]
Cryolite is a relatively rare mineral worldwide. It is most commonly associated with granitic rocks (Ivigtut, Greenland; Miask, Russia; St. Peters Dome, Colorado), and rarely with carbonatites (Goldie, Colorado) and sediments (Green River Formation, USA; Lake Magadi, Kenya) (Bailey, 1980). Very rarely, cryolite also occurs in hydrothermally affected zones of agpaitic alkaline rocks in the Lovozero and Khibiny massifs (Semenov, 1972; Khomyakov, 1995), at Mont Saint-Hilaire (Horvath and Gault, 1990), and in the Saint-Amable sill (Horvath et al., 1998). Well-formed crystals of cryolite are exceedingly rare and were essentially known only from a single locality, Ivigtut, in South Greenland (Krenner, 1883; Boggild, 1953; Petersen, 1993), until their discovery in 1975 in the Francon quarry (Sabina, 1976, 1979). After weloganite, the splendid and exceptionally well-formed yellow cryolite crystals collected in 1975 are arguably the most attractive collectible mineral specimens found in the Francon quarry. At the time, they represented perhaps the largest and the best formed crystals known for this species. In recent years, considerably larger (up to 5 cm) crystals have been found at Mont Saint-Hilaire; however, they are not as well-formed, or colorful, as the Francon specimens.
Cryolite is uncommon in the Francon quarry where it is found as very sharp crystals in both the upper and lower sills. The crystals are transparent to opaque, either colorless or yellow, and typically 1-3 mm in size, with a few exceptional crystals over 1 cm in diameter. Many of the larger yellow crystals have a dull to waxy, grainy or spongy, pseudomorphous or etched appearance. The colorless crystals have a vitreous to adamantine luster. Cryolite is monoclinic but exhibits very pronounced pseudo-cubic symmetry. Unlike the better-known Ivigtut crystals, which appear pseudocubic with dominant {110} prisms and well developed {001} pinacoids, the only habit of Francon quarry crystals is dipyramidal (pseudo-octahedral). The most common forms are dominant {111} and {[bar.1]11} bipyramids, modified by minor {001}, {010} and {100} pinacoids. These common forms are observed on practically all crystals. Additional, usually minor, forms observed on small colorless crystals are: pyramids {112} and {11[bar.2]}, prisms {110}, {011}, {210}, {120}, {021}, {023} and pinacoids {101}, {10[bar.1]}, {201}, {20[bar.1]}, {101}, {10[bar.1]}, {203} and {20[bar.3]}. It is interesting to note that the main morphological feature of Francon cryolite crystals, dominant {111} and {11[bar.1]} bipyramids, is also seen on cryolite crystals from Mont Saint-Hilaire and the Saint-Amable sill. Contact twinning is common in the smaller colorless Francon crystals but the twin laws represented have not been determined.
The colorless crystals are associated with calcite, dresserite, hydrodresserite, dawsonite, and weloganite in the upper sill, and with siderite, calcite, gibbsite, quartz, doyleite and dawsonite in the lower sill. The larger yellow crystals were all found in August 1975 in a unique assemblage in a very small zone of the lower sill near the northwest wall. All the yellow cryolite came from a single blast and specimens were collected over a period of two weeks by two of the authors (LH and EPH) and Donald Doell (Chamberlain and Doell, 1982). The assemblage, in addition to cryolite, included pale gray to white weloganite, including a rare tabular habit, colorless sprays of elpidite, white powdery masses of gibbsite, colorless barite, white strontianite, colorless calcite, and marcasite. The larger opaque, yellow crystals, mostly simple bipyramids, averaged 5-8 mm in diameter with many crystals over 1 cm and a few exceptional ones up to 2.5 cm in diameter. An interesting feature of most of the yellow, bipyramidal cryolite crystals is the conspecific epitactic overgrowth of small, lustrous, colorless cryolite crystals on the corners (represented by the pinacoids {001}, {010} and {100}) and on the crystal edges of the bipyramids (in the [011] zone). These colorless crystals tend to be morphologically more complex than the larger substrate crystals.
Perimorphs after cryolite have been found in both the upper and lower sills. These consist of dull, frosty white, thin shells, retaining the cryolite morphology, composed of gibbsite or fluorite admixed with doyleite. The original cryolite has been partially or completely leached out. A very similar mineral assemblage has been observed at the nearby Saint-Amable sill, except that at Saint-Amable, the gibbsite and doyleite are also closely associated with thomsenolite, a common alteration product of cryolite (Horvath et al., 1998).
Cryolite fluoresces very bright white and creamy white under shortwave ultraviolet radiation, greenish yellow under medium-wave, and brownish yellow under longwave. A weak, white phosphorescence of short duration is observed after exposure to shortwave and medium-wave ultraviolet radiation.
A few gemstones have been faceted from crystals of Francon cryolite. A colorless 0.23-carat, modified kite step-cut stone containing many inclusions is in the collection of the Canadian Museum of Nature (W. Wight, personal communication, 2004).
Dachiardite-Na [Na.sub.2.5][K.sub.0.5][Ca.sub.0.5][[Al.sub.4][Si.sub.20][O.sub.48]*13[H.sub.2]O
Dachiardite, a rare zeolite, was first described from San Piero in Campo, Elba, Italy by D'Achiardi in 1906. A sodium-rich variety was first reported from Orli di Fassa, Alpe di Siusi, near Bolzano, Italy by Alberti (1975), and has subsequently been found at several other localities including the Francon quarry (Bonardi et al., 1981). Under the current zeolite nomenclature, dachiardite from the original type locality in Elba is dachiardite-Ca and the sodium analog is dachiardite-Na with Alpe di Siusi as the type locality (Coombs et al., 1997). The Francon quarry is the first and only known locality in Canada.
At Francon, dachiardite-Na is very rare and was first found in the lower sill where its occurrence was restricted to only a few cavities at the north end of the quarry. The mineral was later found in the alcove on the upper level in some minor sills. The material described by Bonardi et al. was collected by Donald Doell from the lower sill in 1974; it was originally thought to be a potentially new species and was designated APS No. 9. Further investigations revealed that it was a "sodium-rich dachiardite" (Bonardi et al., 1981), now dachiardite-Na. The composition given by Bonardi et al. (1981) is: Si[O.sub.2] 70.10, [Al.sub.2][O.sub.3] 10.44, CaO 0.02, SrO 0.07, [Na.sub.2]O 5.18, [K.sub.2]O 0.98, [H.sub.2]O 12.76 (by DTA/TGA analysis), total 99.55 weight %, resulting in the empirical formula ([Na.sub.2.93][K.sub.0.36][Sr.sub.0.01]-[Ca.sub.0.01])[.sub.[SIGMA]3.31]([Si.sub.20.47][Al.sub.3.59])[.sub.[SIGMA]24.06])[O.sub.48]*12.48 [H.sub.2]O, based on 48 oxygen atoms. The 5.18% [Na.sub.2]O content is one of the highest known for the species, and is higher than the 4.47% reported for dachiardite-Na from the type locality (Alberti, 1975).
In the lower sill dachiardite-Na occurs as masses lining cavities (covering many [cm.sup.2]), and as distinct, individual bundles and divergent sprays, up to 5 mm across, of silky to dull, white, beige to pale brownish, acicular to fibrous crystals up to 4 mm long. Individual crystals are bladed and elongated along [010], with poorly defined faces, becoming splintery and fibrous at the terminations. They are transparent to translucent; fragments are colorless. Contrary to Bonardi et al. (1981), who reported that the dachiardite-Na occurred in a single cavity, two of the authors (LH and EPH) have found the mineral in at least two others. The Doell specimens are from a cavity (23 cm in maximum dimension) that was lined with colorless analcime, quartz, ankerite and calcite; the cavity walls were entirely covered by a continuous layer of densely intergrown bundles and tufts of white dachiardite-Na crystals. The specimens of dachiardite-Na collected by the authors are significantly different in their paragenesis and even in the physical appearance of the crystals. The specimens are from cavities 5-7 cm in diameter, lined with analcime, mostly covered by a layer of small crystals of beige to pale brown ankerite and pale yellow calcite. From this lining extend small bundles and divergent sprays of beige to pale brownish, acicular crystals up to 4 mm long, invariably associated with small, white, matted masses of finely fibrous mordenite, and colorless weloganite. In the Doell specimens, dachiardite-Na is a very late-stage mineral, whereas in the authors' specimens it is one of the early minerals in the assemblage, sometimes partially or fully overgrown by ankerite, weloganite and calcite. Other associated minerals include aegirine, albite and marcasite.
In 1982, dachiardite-Na was found in the alcove on the upper level in what appear to be amygdaloidal basaltic sills (A. P. Sabina, personal communication, 2005). The amygdules are generally filled with white minerals, and give the dark, brownish gray rock a spotted appearance. Dachiardite-Na occurs as white, usually radiating, fibrous masses filling amygdules 1-2 mm across. Other minerals in the amygdules include dolomite, feldspar, quartz and mordenite. Both the mordenite and the dachiardite-Na are white and fibrous, and difficult to distinguish visually.
Dachiardite-Na fluoresces weakly orange-white under shortwave; weakly orange under medium-wave; and weakly brownish orange under longwave ultraviolet radiation. No phosphorescence was observed.
Dawsonite NaAl(C[O.sub.3])(OH)[.sub.2]
Dawsonite is a relatively common species in the igneous rocks of the Monteregian alkaline province in the Montreal area. The many occurrences include the type locality on the campus of McGill University (Harrington, 1875, 1878; Graham, 1908; Stevenson and Stevenson, 1965, 1977), Mont Saint-Hilaire (Chao et al., 1967; Horvath and Gault, 1990), Mont Saint-Bruno (Mandarino and Harris, 1965; Stevenson and Stevenson, 1978), the Miron quarry in Montreal (Sabina, 1978), the Saint-Amable sill (Horvath et al., 1998) and several unpublished localities. In the Francon quarry, dawsonite is the most common and abundant mineral. It is a major component of the sill rock (Steacy and Jambor, 1969; Jambor et al., 1976; Vard and Williams-Jones, 1993), and is present in a large proportion of the sill cavities (Sabina, 1976).
In the sill cavities, dawsonite occurs as superb, well-formed, colorless crystals ranging in size from less than 1 mm up to 2 cm long. The crystal morphology is very simple, predominantly defined by only two forms. Several common crystal habits can be recognized:
Habit A consists of short prismatic crystals with a dominant {110} prism, terminated by a {001} basal pinacoid, rarely modified by a small {010} pinacoid. The crystals are 0.2-3 mm in length. In this habit, dawsonite occurs as scattered individual crystals on other minerals, and as compact spherical aggregates and open clusters of radiating crystals. Composite crystals consisting of two or more prisms in parallel to semi-parallel growth are common. This is a very common habit in both the upper and lower sills.
Habit B is characterized by blocky to equant crystals with the same forms as in habit A but with more common and prominent {010} and {100} pinacoids. The crystals are typically 1-3 mm with exceptional crystals up to 1 cm across; the larger crystals sometimes form plate-like, parallel-growth aggregates up to 3 cm across. This is a common habit in both upper and lower sills.
Habit C crystals are tabular, colorless to opaque white, 1-4 mm in diameter, with dominant {001} basal pinacoids. This habit is very rare and localized.
Habit D is characterized by acicular crystals consisting of elongated, slender {110} prisms terminated by the {001} pinacoid, very rarely modified by a {011} prism. Most of these crystals are 6-10 mm long (aspect ratio ~1:10), and rarely up to 2 cm long (aspect ratio of 1:20-30); in the extreme case they are hair-like. Dawsonite with this habit is most common in the upper sill where it occurs as dense masses of radiating and randomly oriented crystals.
Habit E consists of fibrous to capillary crystals in white, matted, cotton-like, and compact fibrous to pulverulent masses. This habit is rare and very localized.
Dawsonite crystals are typically striated parallel to [001] on the prism faces, which imparts a silky luster. In contrast, the luster of the {001} basal pinacoids is vitreous.
Dawsonite has also been reported as white waxy spheres; and as flaky, scaly and botryoidal aggregates (Sabina, 1976, 1979).
Dawsonite is ubiquitous in the sill cavities. It occurs as more than one generation, and is associated with virtually all the minerals known from the quarry. The largest, and undoubtedly the best crystals of dawsonite were the blocky (habit B) crystals found in the lower sill in the northwest end of the quarry in the fall of 1976. The largest single crystals from this find are up to 1 cm long, and some plate-like aggregates are up to 3 cm across. These are characteristically associated with quartz, sprays of pinkish celestine, and goethite. Excellent specimens with cavities several cm across, lined with masses of acicular crystals up to 1 cm long, were common and easy to collect during 1973-1976, from the upper sill at the south end of the quarry near the entrance ramp. Some cavities were lined by dawsonite only and others by dawsonite intergrown with cubes of deep purple fluorite and orange sphalerite. In the same zone, there were very unusual cavities containing only dawsonite and quartz. In some of these, the dawsonite is partially overgrown by bluish gray, drusy quartz, and some fine, acicular, second-generation dawsonite, including exceptionally long acicular crystals (up to 2 cm long). Very late-stage dawsonite in massive form is fairly common in the upper sill. In an occurrence discovered in 1981 in the alcove, white, pulverulent, very finely fibrous masses (habit E) partially filled cavities up to 8 cm across, and encrusted the associated weloganite, quartz, calcite and first-generation dawsonite. The satiny luster and effervescence in dilute HCl helps to distinguish this form of dawsonite from some of the other Francon minerals that occur as white crusts. Although dawsonite is often described as being "soluble in acids with effervescence" (Palache et al., 1951), it should be noted that larger crystals such as those found at Francon display effervescence only in warm or concentrated hydrochloric acid.
Dawsonite has also been found in the limestone adjacent to the lower sill. In 1980, an open fracture yielded randomly oriented acicular crystals up to 1.5 cm in length associated with calcite and strontianite.
Most dawsonite is not fluorescent, but exceptionally, some has been observed to fluoresce pale yellow to pinkish yellow under shortwave, medium-wave and longwave ultraviolet radiation.
Dickite [Al.sub.2][Si.sub.2][O.sub.5](OH)[.sub.4]
Dickite has been identified as a silky white coating on quartz (A. P. Sabina, personal communication, 2004). Dickite is a polymorph of halloysite and kaolinite, which also occur in the quarry.
Dolomite CaMg(C[O.sub.3])[.sub.2]
Dolomite is an uncommon cavity mineral in the lower sill, where it occurs as colorless, pale yellow and pale pink rhombohedra less than 1 mm across, often in association with ankerite, calcite and siderite. Visually it is not readily distinguishable from similarly colored associated rhombohedral carbonates. Dolomite has also been found in cavities in the upper sill and in dikes. In an unusual assemblage in a dike in the alcove, dolomite occurred as colorless, saddle-shaped rhombohedra up to 2 mm, occasionally forming drusy cavity linings, in association with analcime, quartz, mordenite and synchysite-(Ce). Dolomite also forms granular patches in the dike rock. Dolomite is common in limestone cavities as translucent, white and brownish, saddle-shaped rhombohedra up to 5 mm across, associated with strontianite, calcite, quartz and, less commonly, pyrrhotite.
Doyleite Al(OH)[.sub.3]
Doyleite, a triclinic polymorph of nordstrandite, beyerite and gibbsite, was described as a new species jointly from Mont Saint-Hilaire [type locality 1] and from the Francon quarry [type locality 2] (Chao et al., 1985). The structure was solved by Clark et al. (1998) using Mont Saint-Hilaire material, the only known source for well-formed crystals. Since its original description, doyleite has also been reported from Gjerdingen, Nordmarka, Norway (Raade, 1990); Grube Clara, Oberwolfach, Germany (Walenta, 1993); the Coldstones quarry, Pately Bridge, North Yorkshire, England (Young et al., 1997); the Saint-Amable sill, Varennes and Saint-Amable, Quebec (Horvath et al., 1998); and the Gold Quarry mine, Eureka County, Nevada (Castor and Ferdock, 2003).
At Mont Saint-Hilaire doyleite was first recognized as a potentially new species in 1974 and was designated as UK45; at the Francon quarry it was first noted in 1977 and was designated as APS No. 11 (Sabina, 1979). The composition given by Chao et al. (1985) for Francon quarry doyleite is: [Al.sub.2][O.sub.3] 59.6, Si[O.sub.2] 3.22, CaO 0.23, MgO 0.96, FeO 0.08, [Na.sub.2]O 0.35, [H.sub.2]O 39.56 (calculated by difference), total 100.00 weight %. In contrast, Mont Saint-Hilaire doyleite contains much less Si and no Mg.
At the Francon quarry, doyleite occurs as a late-stage mineral in both the upper and lower sills. It forms dull, translucent to opaque, white, creamy white or bluish white irregular granular or porcelaneous aggregates, compact, botryoidal and spherical aggregates, and thin crusts, commonly on cryolite, weloganite, strontianite and calcite crystals. Other associated minerals include albite, barite, dresserite, hydrodresserite, strontiodresserite, quartz, dawsonite, fluorite, analcime, halloysite and montroyalite. At very high magnification the doyleite aggregates appear to consist of columnar crystals with a roughly square cross-section. Admixed with gibbsite, doyleite commonly forms thin, shell-like perimorphs after cryolite from which the original cryolite has been partially or completely leached out. A similar association of doyleite with cryolite and gibbsite has been noted in the Saint-Amable sill (Horvath et al., 1998). Visual identification of doyleite is unreliable because of its resemblance to other white, powdery aggregates and crusts. Furthermore, although doyleite is not fluorescent under ultraviolet radiation (Chao et al., 1985), its presence is usually masked by the strong fluorescence of admixed gibbsite. For these reasons, its rarity is difficult to assess.
Dresserite Ba[Al.sub.2](C[O.sub.3])[.sub.2](OH)[.sub.4]*[H.sub.2]O
Dresserite was noted as a potentially new species, along with weloganite, very early in the mineralogical investigation of the quarry, and was designated as APS No. 4. It was first mentioned as a "new barium analog of dundasite" by Sabina et al. (1968) and was subsequently described as a new species by Jambor et al. (1969). Its infrared characteristics were investigated by Farrell (1977). Although its structure remains undetermined, Jambor et al. (1977a) concluded that it was unlikely to be isostructural with its chemical analog, dundasite. The Francon quarry remains the only known locality for dresserite. However, a Ca-analog, from the Many coal deposit, Tatabanya, Hungary, has recently been approved as a new species (Burke and Ferraris, 2005).
When dresserite was first described, Jambor et al. (1969) reported that "another hydrous barium aluminum carbonate, which is not megascopically distinguishable from dresserite" had also been found. This proved to be the new species hydrodresserite (Jambor et al., 1977b). Jambor et al. determined that hydrodresserite dehydrates to dresserite, and that some dresserite is in fact pseudomorphous after hydrodresserite. (This is discussed in more detail below, under hydrodresserite.)
Dresserite has been found only in the upper sill, where it is relatively common, and it is especially abundant in the alcove area. It occurs as white to pale cream, compact, spherical aggregates of radiating, colorless, fibrous to thin-bladed crystals. The spheres are 1-6 mm in diameter, with a dull to sub-vitreous luster on the exterior, and a silky luster on freshly broken interior surfaces. They often form botryoidal clusters, rarely up to 2 cm across. The exterior surface of the individual spheres may be smooth, rough due to slightly projecting crystals, or it may have random, colorless bladed crystals extending some distance from the surface. These crystals may be dresserite, hydrodresserite or dresserite pseudomorphs after hydrodresserite. Dresserite is orthorhombic, with the bladed crystals elongated along [001] and flattened on (010) (Jambor et al., 1969) and "bluntly terminated" (Sabina, 1979) by what is likely a {001} pinacoid. Bladed crystals corresponding to {010}>{100}>{001} forms are visible under the microscope and on SEM photographs. Although cleavage was not reported by Jambor et al., (1969), possible cleavage or parting, and what may be best described as lamination parallel to [010] is apparent in SEM photos. Identical features are observed on hydrodresserite, which has a perfect {010} cleavage. The available evidence suggests that crystals with an orthogonal termination are primary dresserite, and those with the distinct, inclined {102} pinacoid termination are either hydrodresserite or dresserite pseudomorphs after hydrodresserite. In the smooth-surfaced spherules, the two species are indistinguishable.
Associated minerals include practically all the species found in the upper sill, but the invariably and intimately associated species is hydrodresserite. Also very common are weloganite, quartz, calcite and dawsonite. Dresserite is one of the latest minerals in the paragenetic sequence, and is often found perched on quartz and weloganite, resulting in rather attractive specimens.
Dresserite fluoresces strongly yellowish white under shortwave and medium-wave, and greenish yellow under longwave ultraviolet radiation, and gives a medium to weak, white, short-duration phosphorescent response after exposure to all three wavelengths.
Elpidite [Na.sub.2]Zr[Si.sub.6][O.sub.15]*3[H.sub.2]O
Elpidite, considered to be one of the typical indicator minerals of agpaitic rocks, is relatively rare at Francon. It has been found only in the lower sill, in the northwestern part of the quarry. It occurs as colorless, acicular prismatic crystals, 1-3 mm long, with a vitreous luster. The crystals form sheaves, radiating clusters, random and sub-parallel, stacked aggregates; and sometimes, a crust-like layer several square centimeters in area, commonly on analcime crystals. Elpidite crystals consist of a dominant {110} prism terminated by a {001} basal pinacoid, very rarely modified by a small {011} prism. The only significant concentration of elpidite was found during the summer of 1975, mostly with yellow cryolite. Other minerals in the cryolite assemblage are opaque white weloganite, strontianite, barite and powdery gibbsite. Elpidite was also found in the same area of the quarry with yellow weloganite, analcime, calcite, albite, marcasite, synchysite-(Ce) and brookite. Elpidite fluoresces a medium-intensity greenish yellow under shortwave ultraviolet radiation. The fluorescence, vitreous luster and lack of striations on the prism faces help to distinguish elpidite from superficially similar dawsonite.
Fluorite Ca[F.sub.2]
Fluorite is one of the more common cavity minerals in the sills. It is somewhat more abundant in the lower sill than in the upper sill. Rarely, it is also found in dike cavities. It occurs as isolated individual crystals 1-5 mm in diameter; as crystal aggregates and drusy cavity linings; as platy, botryoidal, and granular masses; and as finely disseminated inclusions coloring other minerals.
The crystal morphology is simple, with {100} cubes being the most common, and {111} octahedra also quite common; the combination of the two is less common. Another, relatively rare form noted is the typically small {101} dodecahedron. Some crystals display prominent growth offsets on the cube faces.
The color of the most common crystals varies from a transparent and pale to vivid purple, to translucent to opaque and dark purple to almost black. Colorless crystals are less common, and dull, opaque white crystals are rare. Patchy, irregular color zoning, phantoms and color spots (mostly pinkish violet) are relatively common. Some crystals are colored reddish by minute hematite inclusions, and hematite sometimes coats the edges of the crystals.
A very rare and unusual variety of fluorite consists of tiny, vitreous, colorless spheroids, forming botryoidal crusts reminiscent of hyalite opal. Similar, individual, translucent white spheroids of fluorite have been observed on calcite.
Fluorite is an intermediate to late-stage mineral, sometimes found as two distinct generations in the lower sill, associated with nearly all the cavity minerals in the sills, but most consistently with dawsonite. In dike cavities, colorless fluorite has been found with mordenite, analcime, dolomite, cristobalite and synchysite-(Ce).
Franconite [Na.sub.2][Nb.sub.4][O.sub.11]*9[H.sub.2]O
Franconite was first found in the Francon quarry around 1976 and was designated as APS No. 10 (Sabina, 1979). An identical mineral was found at Mont Saint-Hilaire in 1975 by two of the authors (LH and EPH); it was recognized as a potentially new species and designated as UK43 (Chao and Baker, 1979). In 1984, franconite was described as a new species from the Francon quarry by Jambor et al. who noted that UK43 from Mont Saint-Hilaire was "probably franconite." Mont Saint-Hilaire then became the second known locality (Wight and Chao, 1986). Franconite has also been reported from the Vishnevye Gory massif, South Urals, Russia (Nikandrov, 1989), the Saint-Amable sill, Varennes and Saint-Amable, Quebec (Gault and Horvath, 1994; Horvath et al., 1998), and the Vuoriyarvi massif (Subbotin et al., 1997a and b) and Kukisvumchorr in the Khibiny massif (Pekov and Podlesny, 2004), both in the Kola Peninsula, Russia.
Franconite occurs in cavities in the upper sill as very tiny (up to 250 [micro]m diameter), opaque white globules, commonly forming clusters up to 0.5 mm in diameter (Sabina, 1979; Jambor et al., 1984). At high magnification (SEM), the globules are seen to consist of radiating, elongated bladed crystals with obtuse terminations displaying two faces. The globules have a porcelaneous, relatively smooth surface, and an interior silky luster when split. Their external appearance is quite different from the more open spherical aggregates of radiating fibers found at Mont Saint-Hilaire. However, the individual crystals have the same morphology at both localities; the forms have not been determined. The average chemical composition of franconite from the Francon quarry yields the following empirical formula: ([Na.sub.1.69][Ca.sub.0.12][Sr.sub.0.01])[.sub.[summation]1.82]-([Nb.sub.3.81][Ti.sub.0.09][Al.sub.0.01][Si.sub.0.09])[.sub.[summation]4.00][O.sub.10.88]*9[H.sub.2]O (Jambor et al., 1984). Although not mentioned in the original description, some franconite contains calcium in solid solution, as well as intergrown hochelagaite, as reported by Jambor et al. (1986), which would account for the calcium in the above empirical formula. (This is discussed further below, under hochelagaite.)
Jambor et al. (1984) reported that franconite from the Francon quarry does not fluoresce under ultraviolet radiation; in contrast, franconite from Mont Saint-Hilaire and the Saint-Amable sill fluoresces under both shortwave and longwave radiation (Horvath and Gault 1990; Horvath et al. 1998). The similarity of franconite to other white globular minerals makes its visual identification unreliable. However, the porcelaneous appearance of individual globules, and their tendency to occur isolated on crystals of weloganite (most commonly), calcite, quartz and cryolite are good indicators of its potential presence. Other commonly associated minerals include dawsonite, gibbsite, barite, strontianite and dresserite. In the presence of coatings of bitumen, franconite sometimes occurs on top of the coating (Sabina, 1979).
Galena PbS
Galena at the Francon quarry is relatively common and widespread in very small quantities, especially in the lower sill cavities. It occurs as usually isolated, sharp octahedral crystals generally 1-5 mm in diameter, with exceptional crystals to 1.5 cm in diameter. The morphology is rather consistent, with most crystals exhibiting dominant {111} octahedral faces, sometimes modified by small {100} cube faces. No other forms have been observed. The crystals commonly have a bright metallic luster. Rarely, the crystal faces are coated with pyrite crystals, and very rarely, with thin, film-like alterations of cerussite and hydrocerussite (Sabina, 1979: Sabina, 1992). Galena is most commonly associated with dawsonite, fluorite, marcasite, calcite, quartz, sphalerite, weloganite, celestine, and rarely with barite, cryolite, elpidite and gibbsite.
Garronite-like mineral Na[Ca.sub.2.5][Al.sub.6][Si.sub.10][O.sub.32]*14[H.sub.2]O
A mineral designated as APS No. 14 has been shown to be related to garronite (Na[Ca.sub.2.5][[Al.sub.6][Si.sub.10]][O.sub.32]*14[H.sub.2]O) but contains very little calcium and may be a new sodium analog. Sabina (1992) lists it as "garronite (Na)." The mineral was found as a transparent, yellow to orange crystalline filling in amygdules 2-5 mm across, in a dark sill rock with a spotted appearance (A. P. Sabina, personal communication, 2005). The sill, about 60 cm thick, was exposed below the upper phonolite sill in the alcove. Rimming the "garronite (Na)" are white, sugary "K-feldspar," and dolomite. Other minerals occurring in the sill were dachiardite-Na, mordenite, calcite, ankerite, and siderite. "Garronite (Na)" was also found in other locations in the alcove, in what may be the same sill.
Work on the mineral has been carried out at the Geological Survey of Canada by A. C. Roberts who has provided the data reported here. Electron microprobe analyses (WDS) indicate a large variation in the alkali and alkali-earth content, with Na consistently much greater than Ca: [Na.sub.2]O 4.18-9.58, [K.sub.2]O 0.39-1.15, MgO 0.19-0.42, CaO 0.05-0.40 weight %. In contrast, garronite sensu stricto is commonly Na-poor, with (Na + K) < 0.2 apfu (Coombs et al., 1997). APS No. 14 shows a large variation in the Si/Al ratio. A preliminary structure analysis indicates the presence of (Si,Al)[.sub.16][O.sub.32] groups as in garronite. The mineral has a monoclinic symmetry, space group I2/m or I2, a = 9.970, b = 9.968, c = 10.074 [Angstrom], [beta] = 90.143[degrees], with V = 1001.2 [[Angstrom].sup.3]. The strongest X-ray powder-diffraction lines are (d[Angstrom](I)): 7.09(90), 4.997(50), 4.095(70), 3.164(100), 2.675(40). The measured density is 2.167 g/c[m.sup.3].
Gibbsite-like mineral Al(OH,F)[.sub.3]
The mineral initially designated as APS No. 3 (Sabina, 1976) was later established to be a gibbsite-like mineral containing an unusually high content of fluorine, and differing in other respects from gibbsite (Jambor et al., 1990). It may well be a new species but the available material precludes a structure determination. Three sets of analyses reported by Jambor et al. show a wide compositional range: MgO 0.4-0.7, CaO 0.5-0.7, [Al.sub.2][O.sub.3] 52.5-66.1, Si[O.sub.2] 1.5-10.5, F 4.8-8.3, [H.sub.2]O 20.9-24.0 weight %. Jambor et al. concluded that the high silica content probably represents disseminated amorphous silica.
Fluorine-bearing gibbsite is relatively common at the Francon quarry, in cavities in the upper and lower sills as pure white to pale cream, powdery to granular coatings, porcelaneous and waxy granular aggregates, botryoidal crusts, and globules. It also forms shell-like epimorphs after cryolite crystals, in which the cryolite has been partially or completely leached away. The globules are 0.1-0.2 mm in diameter and consist of radial aggregates of divergent fibers. Under high magnification (SEM) the fibers appear as stepped columns with a pseudo-hexagonal cross-section. Jambor et al. reported that the botryoidal crusts generally have an area of no more than 1 to 2 m[m.sup.2], but encrustations covering several square centimeters have been observed. In the coatings, aggregates, crusts and epimorphs, F-bearing gibbsite is often found intermixed with its triclinic polymorph, doyleite. F-bearing gibbsite is fluorescent a medium-bright whitish yellow (4) under shortwave, medium-wave and longwave ultraviolet radiation, and displays a weak, white phosphorescence after irradiation with shortwave and mediumwave ultraviolet radiation. Although the fluorescence of F-bearing gibbsite is helpful in distinguishing it from non-fluorescent doyleite, it also masks the presence of intermixed doyleite.
F-bearing gibbsite is a late-stage mineral and has been observed to occur on weloganite, strontianite and calcite, sometimes completely coating the crystals as in the case of the cryolite epimorphs. Other associated minerals include elpidite, barite, dawsonite, fluorite, halloysite and quartz.
Gismondine [Ca.sub.4]([Al.sub.8][Si.sub.8][O.sub.32])*16[H.sub.2]O
A mineral with an X-ray diffraction pattern closely fitting that of gismondine was found in the lower sill. It is very rare and occurs as irregular aggregates less than 2 mm across, of dull, opaque, pale gray subhedral crystals associated with dull white weloganite (habit G), analcime, albite, marcasite, calcite and dolomite. Chemical analyses are needed to fully confirm this identification.
Glauconite series [K.sub.0.8][R.sub.1.33.sup.3+][R.sub.0.67.sup.2+][square][Al.sub.0.13][Si.sub.3.87][O.sub.10](OH)[.sub.2]
A member of the glauconite series has been identified on a specimen of sill rock (GSC APS 606). It occurs as velvety black stringers 2-3 mm long. Sabina (1994) has also reported a mineral related to glauconite, or perhaps celadonite, in the sill rock.
Gmelinite series ([Na.sub.2],Ca,[K.sub.2])[.sub.4][[Al.sub.8][Si.sub.16][O.sub.48]]*22[H.sub.2]O
Gmelinite occurs very rarely in cavities in the upper sill in the alcove as colorless, tabular crystals to 3 mm, associated with quartz and dolomite (A. P. Sabina, personal communication, 2004). The specific member of the gmelinite series under the current zeolite nomenclature has not been determined.
Goethite [alpha]-[Fe.sup.3+]O(OH)
Goethite is relatively common in some lower sill cavities where it occurs as orange-yellow to brownish yellow, short, fibrous to acicular crystals forming tufts, sprays, spherical aggregates and attractive velvety coatings on other minerals, most notably on celestine and dawsonite. The tendency for goethite to preferentially coat celestine is well illustrated in specimens in which bundles and sprays of celestine crystals are completely encrusted by velvety goethite, whereas other minerals in the same cavity remain totally uncoated or only lightly sprinkled with small tufts. Other commonly associated minerals are calcite, quartz, ankerite, hematite and fluorite.
Graphite C
Small black patches of graphite, less than 5 mm in diameter, consisting of soft, foliated masses of thin, irregular lamellae, occur in the sill rock. Graphite is very rare at the Francon quarry. Associated minerals include dawsonite, almandine, quartz, nahcolite and halite.
Gypsum CaS[O.sub.4]*2[H.sub.2]O
Gypsum is relatively rare at the Francon quarry. Exceptionally large, colorless cleavage masses, up to 10 cm thick and 30 cm across, are in the GSC collection. They were donated by the quarry superintendent, who indicated that they were found at a sill-limestone contact (A. P. Sabina, personal communication, 2005; D. V. Doell, personal communication, 2005). Gray, fine-grained rock attached to one of the specimens has the typical appearance of sill phonolite. Gypsum has also been found in dikes as platy masses up to 5 cm across; as aggregates, several centimeters across, of sharp, colorless, tabular crystals up to 1 cm long in cavities associated with analcime and celestine; and as colorless veins associated with pyrite, dolomite and chalcedonic quartz. Acicular crystals and rosettes associated with natrojarosite, from an unspecified environment, were reported by Sabina (1979). Gypsum fluoresces a medium-bright whitish yellow and orange under shortwave, medium-wave and longwave ultraviolet radiation.
Halite NaCl
In a rare occurrence, halite was found as white stringers of very tiny granules, and irregular, fine powdery patches, admixed with nahcolite, on the surface of broken rock from the lower sill. It may be a residue from the evaporation of the liquid that is commonly released from freshly opened cavities. Halite and nahcolite both occur in inclusions in cavity minerals (Vard and Williams-Jones, 1993).
Halloysite [Al.sub.2][Si.sub.2][O.sub.5](OH)[.sub.4]
Both hydrated (10[Angstrom]) and dehydrated (7[Angstrom]) halloysite have been identified by X-ray diffraction (Sabina, 1994). It occurs in cavities in both upper and lower sills as microscopic intergrowths with gibbsite (Jambor et al., 1990); as white globular aggregates associated with pyrrhotite, cryolite, weloganite and quartz; and as chalky white coatings on quartz and albite. Other associated minerals in the upper sill include dresserite, hydrodresserite, strontiodresserite, doyleite and montroyalite. Halloysite has also been observed in sill rock as waxy, amber masses along the margins of a cavity, as embedded, tan, earthy laths associated with kaolinite and analcime, and as bluish-white to white coatings on a fracture surface.
Halotrichite [Fe.sup.2+][Al.sub.2](S[O.sub.4])[.sub.4]*22[H.sub.2]O
Halotrichite occurs very rarely as a white to pale gray, fine, fibrous, supergene efflorescence on altered pyrite and marcasite, typically associated with other alteration products such as rozenite, sulfur and natrojarosite.
Harmotome ([Ba.sub.0.5],[Ca.sub.0.5],K,Na)[.sub.5][[Al.sub.5][Si.sub.11][O.sub.32]]*12[H.sub.2]O
Harmotome is extremely rare at the Francon quarry, known from only a few confirmed specimens. In a specimen (GSC APS F105) found in an upper sill cavity the harmotome occurs as gray, microcrystalline (clay-like) aggregates encrusting quartz and weloganite, and associated with calcite and fluorite. It has also been observed from an unspecified sill cavity as white to beige, felt-like aggregates consisting of minute (<0.1 mm long) crystals, associated with weloganite (Canadian Museum of Nature specimen CMNMC 49939, identified by X-ray diffraction and EDS).
Hematite [alpha]-[Fe.sub.2][O.sub.3]
A relatively common accessory mineral in cavities in the lower sill, hematite is found as minute, waxy to dull, reddish brown and black globules; as botryoidal aggregates and crusts; as red powdery coatings; and as bright red, flaky or powdery inclusions in dawsonite, celestine, calcite and barite. Hematite in a cavity is a useful indicator of the potential presence of baddeleyite, thorbastnasite and zircon (Sabina, 1979). Other associated minerals include goethite, ankerite, fluorite, marcasite, pyrite, quartz, weloganite and kaolinite.
Hochelagaite (Ca,Na,Sr)[Nb.sub.4][O.sub.11]*8[H.sub.2]O
Hochelagaite, a Ca-dominant analog of franconite (Na-dominant) and ternovite (Mg-dominant), was described as a new species jointly from the Francon quarry and from Mont Saint-Hilaire (Jambor et al., 1986). At the Francon quarry, the mineral was first noted around 1980 and designated as APS No. 13; at Mont Saint-Hilaire it was found in 1979 and recognized as a potentially new species with the designation UK50. Hochelagaite from both localities has a similar overall composition but with a considerable variation in the sodium content. This reflects the presence of sodium in solid solution, and, in the case of Francon hochelagaite, an intergrowth of franconite. In recent years, hochelagaite has also been reported from the nearby Saint-Amable sill, Varennes and Saint-Amable, Quebec (Gault and Horvath, 1994; Horvath et al., 1998); Vardeasen in southern Norway (Andersen et al., 1996); the Vuoriyarvi massif, Kola Peninsula, Russia (Subbotin et al., 1997a and b); the Vishnevye Gory alkaline complex, Russia (Pekov, 2001); and at Kovdor and the Khibiny massif, Kola Peninsula, Russia (I. Pekov, personal communication, 2004).
At the Francon quarry, hochelagaite is considered very rare and is known only from cavities in the upper sill. It is a late-stage mineral like franconite, and occurs as dull to sub-vitreous, white globules, averaging about 150 [micro]m in diameter. The minute globules consist of radiating bladed crystals about 0.03 mm in length, commonly intergrown with thin blades of franconite. Individual crystals are brittle, colorless to translucent white, and have a vitreous luster. Hochelagaite is typically found on crystals of weloganite, calcite and quartz, associated with dawsonite and strontianite. Hochelagaite does not fluoresce under ultraviolet radiation (Jambor et al., 1986), and is visually indistinguishable from franconite and other white globular encrustation minerals.
Humboldtine [Fe.sup.2+][C.sub.2][O.sub.4]*2[H.sub.2]O
Humboldtine is exceedingly rare at the Francon quarry, where it has been found as bright yellow inclusions in quartz (Sabina, 1992, 1994).
Hydrocerussite [Pb.sub.3](C[O.sub.3])[.sub.2](OH)[.sub.2]
A late-stage alteration product, hydrocerussite occurs as white, powdery to granular coatings on galena crystals with cerussite.
Hydrodresserite Ba[Al.sub.2](C[O.sub.3])[.sub.2](OH)[.sub.4]*3[H.sub.2]O
Hydrodresserite was described from the Francon quarry as a new species by Jambor et al. in 1977. Its infrared characteristics were investigated by Farrell (1977), and its crystal structure was solved by Szymanski (1982). The presence of the mineral was noted as early as 1967 when it was designated as APS No. 2. It was first mentioned by Jambor et al. (1968) as a "hydrous barium aluminium carbonate." As the name implies, hydrodresserite differs from dresserite in having three water molecules per formula unit compared to one in dresserite. The Francon quarry remains the only known locality for the mineral.
X-ray diffraction studies by Jambor et al. (1977b) showed that hydrodresserite is unstable under most atmospheric conditions and dehydrates to dresserite, suggesting that some dresserite is pseudomorphous after hydrodresserite. The dehydration process is particularly sensitive to humidity levels, and Jambor et al. found that dehydrated hydrodresserite partially reversed to hydrodresserite after prolonged exposure to a warm water-saturated atmosphere. An infrared analysis of the thermal decomposition of hydrodresserite by Farrell (1977) indicated that, unlike the X-ray diffraction analysis by Jambor et al. (1977b), the conversion to dresserite was incomplete. Observations by the authors suggest that the instability of hydrodresserite may not be as general and consistent as reported, and perhaps varies from sample to sample or from zone to zone in the sill. Several specimens collected in 1974-1975 (a few years after the type material) by two of the authors (LH and EPH) and stored in a collection in a normally very dry Canadian home, were analyzed by X-ray diffraction in 1995 and 2003, and were found to be predominantly if not completely hydrodresserite. The colorless, sharp, bladed crystals that were analyzed showed no visible sign of alteration. Silky white, acicular crystals collected by one of us (PT) in 1968 and analyzed by X-ray diffraction in 2004 were also found to be hydrodresserite. However, bladed crystals with the morphology of hydrodresserite that are opaque white and appear to be altered, and may now be dresserite pseudomorphs after hydrodresserite, have been observed.
Hydrodresserite is relatively common in cavities in the upper sill. Two major modes of occurrence are observed: compact spherical aggregates, and open clusters of radiating crystals. The compact spherical aggregates, up to 3 mm in diameter, consist of radiating, fibrous to bladed crystals. The surface of the spherules has a dull to sub-vitreous luster, and at high magnification it appears mosaic-like as if tiled by tiny rectangular terminal faces. The crystals in these spherules radiate from a common center; on broken interior surfaces they have a silky luster. In spherules with a smooth, mosaic-like surface dresserite and hydrodresserite are visually indistinguishable. Some of the compact spherules have sharp, colorless, individual crystals extending from their surface, and in this case hydrodresserite and dresserite pseudomorphs after hydrodresserite can be readily distinguished from dresserite by their distinct triclinic morphology. In the second mode of occurrence, producing the best formed crystals, hydrodresserite occurs as radiating clusters, sheaves and randomly oriented aggregates of well separated, sharp, colorless bladed crystals up to 2 mm long. These crystals are shorter along [001] than those in the compact spherules. This habit is unique to hydrodresserite, and is often observed side-by-side with compact spherules of dresserite. Hydrodresserite crystals are elongated along [001], and are defined by the {010} (dominant), {2[bar.1]0} and {102} pinacoids (Jambor et al., 1977). In our investigation of the morphology we also noted another prominent pinacoid on SEM photos, not reported before. The form is {[bar.h]10}, most likely {110}, but goniometric measurement is needed for confirmation. Some crystals have swallow-tail terminations. Although twinning in hydrodresserite has not been reported, this may represent contact twinning on (010), or perhaps simply parallel growth of crystal pairs. The SEM photos also show splitting and lamination of the crystals parallel to [010], consistent with the perfect {010} cleavage reported by Jambor et al. (1977). Hydrodresserite has also been found as silky, white, spherulitic aggregates of divergent, acicular crystals, less than 1 mm in diameter. These form continuous cotton-ball-like crusts to 1 cm or more across.
Unlike dresserite, hydrodresserite is non-fluorescent. Weak white fluorescence under longwave ultraviolet radiation has been observed on the cotype (Royal Ontario Museum specimen ROM M34547; R. A. Ramik, personal communication, 2004), but this may be due to the presence of dresserite. Hydrodresserite is invariably associated with dresserite, and most commonly with weloganite, calcite, quartz, marcasite, strontianite and dawsonite, and rarely with cryolite, gibbsite and doyleite. Since hydrodresserite and dresserite coexist in practically all specimens, labeling them as dresserite/hydrodresserite is recommended in the absence of an instrumental analysis.
Ilmenorutile (Ti,Nb,[Fe.sup.3+])[O.sub.2]
Ilmenorutile is found very rarely in the upper and lower sill cavities and along their margins. It occurs as velvety black, submetallic plates, up to 1 mm in diameter; as black hexagonal plates and rosettes; as dull black, granular patches; and as a dull black, thin coating on small rosettes of brookite. It has been observed on crystals of dawsonite, calcite, quartz, and albite. Other associated minerals include weloganite, analcime and barite.
Kaolinite [Al.sub.2][Si.sub.2][O.sub.5](OH)[.sub.4]
Originally designated as APS No. 7 (Sabina, 1976), kaolinite is a relatively rare late-stage cavity mineral in both the upper and lower sill cavities, and is found as waxy to silky, white to creamy white, powdery, granular, flaky, botryoidal and irregular aggregates and masses up to several centimeters across. Botryoidal aggregates are often seen perched on weloganite and dawsonite crystals. Other associated minerals include analcime, ankerite, baddeleyite, barite, calcite, celestine, goethite, hematite, and quartz. Kaolinite fluoresces a medium-bright whitish yellow under shortwave and yellow under medium-wave ultraviolet radiation.
"K-feldspar" KAl[Si.sub.3][O.sub.8]
White to pale pink, platy crystals of "K-feldspar" have been reported from cavities in the lower sill, most commonly associated with analcime, dawsonite and quartz (Sabina, 1979). It has not been determined whether the feldspar is microcline, its dimorph orthoclase, or sanidine.
Orthoclase has been identified as a constituent of the sill rock (Jambor et al., 1976).
Magnetite [Fe.sup.2+][Fe.sub.2.sup.3+][O.sub.4]
Magnetite occurs in the sill rock as small black grains, and very rarely as black, crude subhedral crystals up to 5 mm in diameter.
Marcasite Fe[S.sub.2]
Marcasite is one of the very common species in the Francon quarry, and the most common sulfide. It is found in cavities in both the upper and lower sills and in the limestone, occurring as splendid, acicular, slender prismatic, thin bladed, and thick tabular crystals up to 8 mm, but usually averaging 1-4 mm. The often twinned, bladed crystals form rosettes, fans, v-shaped groups, and stellate aggregates. Crystals are tabular and elongated along [001] with dominant {010} pinacoids, variously developed {110} and {130} prisms, and are invariably terminated by {101} prisms. Contact twinning on {101} is very common. Marcasite is frequently tarnished bluish even in freshly opened cavities. The larger tabular marcasite crystals are sometimes coated with secondary minerals such as natrojarosite, rozenite and halotrichite, and tend to crack after a few years in a collection. However, none has been observed to disintegrate completely, even after 30 years. Thin, bladed crystals show no signs of deterioration, apart from a bluish tarnish. Marcasite is a late-stage mineral and is associated with practically all the species found in the sill cavities. It is often observed as extremely tiny crystals sprinkled on other minerals. Marcasite is much more common than pyrite.
Molybdenite Mo[S.sub.2]
Molybdenite is extremely rare at the Francon quarry. The 2H polytype was found as microscopic, thin flakes associated with weloganite (Sabina, 1979). The only known specimen came from a cavity lined with albite, quartz and calcite (A. P. Sabina, personal communication, 2005).
Montmorillonite (Na,Ca)[.sub.0.3](Al,Mg)[.sub.2][Si.sub.4][O.sub.10](OH)[.sub.2]*n[H.sub.2]O
Originally designated as APS No. 8 (Sabina, 1976), montmorillonite is a relatively common cavity mineral, concentrated in some zones and almost absent in others, in the lower sill. It occurs as white, compact and waxy spherical aggregates 1-2 mm in diameter; as spheres consisting of white, radiating capillary crystals; as matted, fibrous masses forming sheet-like aggregates; and as white, soft, soap-like masses up to several centimeters across partially filling cavities. When exposed to moisture, montmorillonite readily absorbs water and expands, becoming gelatinous. Soap-like masses have been observed to ooze out of open cavities exposed to rain. Associated minerals include celestine, analcime, ankerite, dawsonite, calcite, fluorite, barite, hematite, and rarely mordenite. The expansion of montmorillonite in water is a useful aid to its identification.
Montroyalite [Sr.sub.4][Al.sub.8](C[O.sub.3])[.sub.3](OH,F)[.sub.26]*10-11[H.sub.2]O
Montroyalite was first noted in 1979 and designated as APS No. 12. It was later described as a new species (Roberts et al., 1986), and named montroyalite after the nearby landmark, Mont Royal (Mons Regius in Latin), from which the Monteregian alkaline province takes its name. The Francon quarry remains the only known locality.
Montroyalite was first found in cavities in the upper sill, near the northwest wall, in the alcove. It occurs as dull, translucent to opaque, white to creamy white, rough-surfaced spherules and hemispheres up to 1 mm in diameter, and as botryoidal, powdery to finely fibrous aggregates. The spherules and hemispheres have a compact porcelaneous interior with a waxy luster, and a knobbly to botryoidal exterior surface. The cavities in which montroyalite was originally found were lined with platy albite crystals and less commonly with aggregates of small colorless quartz crystals. Montroyalite, a late-stage mineral, partially covered the lining, and was associated with strontiodresserite, calcite, dawsonite, ankerite, fluorite, and minor barite, strontianite, smythite, marcasite and pyrite. These minerals were in turn covered by a loose to semicompact mass of halloysite intermixed with doyleite.
In another occurrence, spherules of montroyalite were scattered in a cream-colored pulverulent crust, possibly strontiodresserite, and associated only with quartz and albite. In all the specimens examined, montroyalite and strontiodresserite are invariably and intimately associated. Both minerals are considered very rare and only a few confirmed specimens are known. Visual identification of montroyalite is unreliable and proper identification requires instrumental analysis. Montroyalite fluoresces a medium-bright yellow under shortwave, and orange-yellow under medium-wave and longwave ultraviolet radiation.
Mordenite ([Na.sub.2],Ca,[K.sub.2])[.sub.4][[Al.sub.8][Si.sub.40][O.sub.96]]*28[H.sub.2]O
Mordenite, a relatively rare mineral in cavities in the lower sill, is found as silky white tufts, matted felt-like aggregates and compact masses up to several centimeters in diameter, consisting of very fine, capillary crystals up to 1 cm long. Mordenite is often associated with dachiardite-Na, and is sometimes found as inclusions in analcime. Other associated minerals include ankerite, barite, calcite, weloganite, cristobalite, dolomite, quartz, celestine, marcasite, aegirine and pyrite. In 1978, mordenite was found as white, tissue-like aggregates in small cavities in a dike in the alcove area, associated with analcime, dolomite, quartz, strontianite, cristobalite, phillipsite (rare) and synchysite-(Ce). Mordenite is also one of the principal minerals associated with voggite in the type occurrence in a dike in the alcove (Roberts et al., 1990). It has also been observed in one or more minor sills in the alcove associated with dachiardite-Na and a garronite-like mineral.
Mordenite fluoresces weakly pale orange-yellow under short-wave and medium-wave, and a weak pinkish yellow under longwave ultraviolet radiation.
Nahcolite NaHC[O.sub.3]
Nahcolite was identified from the lower sill rock, where it occurs very rarely, admixed with halite, and forming friable, white string-like and irregular, fine powdery patches on the surface of broken rock. It is likely the residue left after the evaporation of the liquid which sometimes spills from freshly opened sill cavities. Nahcolite and halite both occur in fluid inclusions in quartz and other cavity minerals (Vard and Williams-Jones, 1993) and may also be present in the cavity liquid.
Natrojarosite Na[Fe.sub.3.sup.3+](S[O.sub.4])[.sub.2](OH)[.sub.6]
Natrojarosite is most commonly found in the lower sill as an ochre-yellow to orange and orange-brown, dull to waxy, powdery, granular to glaze-like alteration crust on marcasite crystals and rarely on pyrite. It has also been observed on sphalerite in quartzlined fractures in the sill rock (Sabina, 1979).
Natrolite [Na.sub.2][[Al.sub.2][Si.sub.3][O.sub.10]]*2[H.sub.2]O
Natrolite is very rare at the Francon quarry, occurring in a few cavities in the lower sill as clusters of colorless to translucent, dull white, elongated crystals up 1.5 cm long. The crystal morphology is very simple and consists of a {110} prism terminated by {111} pyramids. Crystals are sometimes flattened along [100]. Some crystals are corroded, hollow and etched, resulting in fibrous terminations. Associated minerals include weloganite, albite, barite, analcime, brookite, calcite and siderite. White, elongated, often partially hollow perimorphs consisting of tiny quartz crystals after natrolite crystals up to 1.5 cm long have also been observed in cavities in the lower sill. Natrolite was recognized by the authors (LH and EPH) and confirmed in the course of the present study on specimens collected in 1975. Natrolite gives a weak, white fluorescent response under shortwave, medium-wave and longwave ultraviolet radiation.
Olivine group
Vitreous, reddish to amber, subhedral crystals up to 6 mm in diameter, embedded in a dike rock, have been identified as "olivine" (GSC APS 476). The rock is probably camptonite, which commonly contains phenocrysts of an olivine group mineral.
Paratacamite [Cu.sub.2.sup.2+]Cl(OH)[.sub.3]
Paratacamite was found as green, finely granular aggregates associated with straw-yellow baddeleyite on purple fluorite. The only known specimen (GSC APS 730-8) was collected in 1982 from the west wall of the alcove (A. P. Sabina, personal communication, 2004). This is also the only known occurrence of baddeleyite in the upper sill. To date, no other copper-bearing minerals have been identified from the quarry.
Phillipsite series (K,Na,[Ca.sub.0.5],[Ba.sub.0.5])[.sub.x][[Al.sub.x][Si.sub.16-x][O.sub.32]]*12[H.sub.2]O
An undetermined member of the phillipsite series has been found as very small (less than 0.5 mm) white globules composed of radiating fibers and implanted on dolomite in cavities in a dike (A. P. Sabina, personal communication, 1979). The assemblage, collected in 1978 in the alcove, includes mordenite, analcime and quartz.
Phlogopite K[Mg.sub.3]Al[Si.sub.3][O.sub.10](OH)[.sub.2]
See under biotite series.
Pseudorutile [Fe.sub.2.sup.3+][Ti.sub.3][O.sub.9]
Pseudorutile was reported to occur as black, submetallic, granular patches associated with "K-feldspar," brookite and dawsonite (Sabina, 1979).
Pyrite Fe[S.sub.2]
Pyrite, a relatively common sulfide in both upper and lower sill cavities, and in dike and limestone cavities, occurs as crystals 1-3 mm in diameter, with the cube as the dominant form, often modified by the {210} pyritohedron and {111} octahedron. Simple octahedra {111} have been found in the lower sill, but are quite rare. Pyrite also occurs in the sill cavities as spherules up to 3 mm in diameter, with a lustrous, mirror-like surface composed of numerous cubic microcrystals; and very rarely, as small filiform crystals, sometimes displaying single or multiple 90[degrees] angular articulations. Pyrite has also been identified as granular crusts, fibrous clusters, and botryoidal aggregates. It is associated with practically all the cavity minerals found in the quarry, and is often observed as microcrystals sprinkled on other minerals.
Pyrochlore (Ca,Na)[.sub.2][Nb.sub.2][O.sub.6](OH,F)
Pyrochlore is rare and inconspicuous, occurring as tan-colored octahedra less than 1 mm in diameter disseminated in the upper sill rock (Steacy and Jambor, 1969; Jambor et al., 1976). It has also been reported from unspecified sill rock as orange, granular aggregates associated with barite, pyrite and zircon, and with pseudorutile, siderite and crocoite, in "K-feldspar"-dawsonite inter-growths (Sabina, 1979), and very rarely in sill cavities as orange, resinous aggregates associated with analcime, barite and pyrite (GSC APS 508).
Pyrrhotite [Fe.sub.1-x]S (x = 0.1-0.2)
Pyrrhotite is uncommon in cavities in the lower sill and in dikes. In the sill it is found as bronze-colored metallic, thin tabular, hexagonal crystals and rosette-like aggregates up to 2 mm in diameter, associated with weloganite, dawsonite, fluorite, barite, albite, pyrite, quartz, calcite, cryolite, smythite and doyleite. It has also been found in limestone cavities as plates up to 3 mm in diameter with dolomite, strontianite and calcite. Similarly to marcasite, pyrrhotite crystals typically have a bluish or reddish blue tarnish when collected, or the tarnish may develop after a short period of exposure. Pyrrhotite is similar in appearance to smythite and the two minerals may be difficult to distinguish. Smythite crystals are typically much thinner and foil-like, and are much rarer.
Quartz Si[O.sub.2]
Quartz is one of the most abundant species at the Francon quarry, especially in the upper sill where it occurs as individual crystals from less than 1 mm to 5 cm long, and more often as intricate intergrown groups. There are two main crystal habits: the common, prismatic habit and the rhombohedral habit with minor prism. Both are composed of the same forms, the {10[bar.1]0} prism and the {10[bar.1]1} and {01[bar.1]1} rhombohedrons. Two additional modifying forms, both very rare, have also been observed: a very small {30[bar.3]1} positive rhombohedron, and a minor to well developed {01[bar.1]2} negative rhombohedron. Crystals are transparent to translucent, and colorless to pale gray, and light to dark smoky, some with distinct phantoms, and some appearing almost milky white due to etching. The largest crystals tend to be gray or smoky, and are often skeletal and cavernous due to corrosion.
Some crystals have numerous offsets on the prism faces due to parallel overgrowth. Often the crystals contain inclusions of other minerals, most notably dawsonite, strontianite, marcasite and sphalerite, as well as fluid inclusions (Vard and Williams-Jones, 1993). Colorless small crystals, usually in the 1-3 mm range, often form bow-tie groups, and peculiar artichoke-like aggregates, in which numerous crystals grow from a common center piled on top of and around each other, with terminations pointing in the same direction (Rykart, 1995). The aptly named "artichoke" quartz groups often aggregate into intricately curved and swirling crusts covering cavity walls up to several square centimeters in area. Globular and hemispherical aggregates of very tiny crystals are also observed. Tubular perimorphs of small quartz crystals after natrolite, up to 1.5 cm in length, have been found in the lower sill cavities associated with weloganite, albite, barite, calcite and siderite.
Quartz is an early to late-stage mineral in the cavity paragenesis, and two generations may be observed in the same cavity. In some cavities it forms the wall lining, and it may be the dominant or only mineral present. Quartz also commonly overgrows other minerals including weloganite and dawsonite in the upper sill, and celestine in the lower sill. It can be found with almost any of the cavity minerals in both the upper and lower sills. Very rarely, some quartz found in the upper sill gives a weak orange fluorescent response under shortwave, medium-wave and longwave ultraviolet radiation. This may be caused by inclusions in the quartz.
Chalcedony (cryptocrystalline quartz) has been found in dikes as bluish white masses associated with gypsum, and as bluish white ring-like aggregates on quartz.
Rozenite [Fe.sup.2+]S[O.sub.4]*4[H.sub.2]O
Rozenite is relatively rare and is found as white powdery coatings and globules on oxidized marcasite and pyrite, occasionally associated with natrojarosite and rarely with halotrichite.
Rutile Ti[O.sub.2]
Rutile has been identified in at least one specimen (from a sill cavity) as black, submetallic plates associated with dawsonite, calcite and quartz (GSC APS 709).
Sabinaite [Na.sub.4][Zr.sub.2]Ti[O.sub.4](C[O.sub.3])[.sub.4]
A mineral first found and recognized as a potentially new species by A. P. Sabina was designated as APS No. 5 (Sabina, 1976, 1979). It was later confirmed to be a new species, and named sabinaite after its discoverer (Jambor et al., 1980). It has subsequently also been found at Mont Saint-Hilaire, the only other known locality for the mineral. An investigation of the Mont Saint-Hilaire sabinaite by Chao and Gu (1985) resulted in revised cell parameters, and a revised, currently accepted ideal formula. The structure of sabinaite was solved by McDonald (1996) using crystals from Mont Saint-Hilaire, where sabinaite is found in pegmatites as superb, colorless or transparent, pale yellow, tabular crystals up to 8 mm long, sometimes forming aggregates several centimeters in diameter (Horvath and Gault, 1990; Horvath and Horvath-Pfenninger, 2000).
In the Francon quarry, sabinaite is quite rare, occurring in cavities in the upper sill as white, opaque powdery coatings and crusts on cavity minerals, and as compact, chalky aggregates. The aggregates consist of microscopic flakes and thin, platy crystals with an irregular and roughly hexagonal outline, typically less than 0.01 mm in diameter and 0.001 mm thick (Jambor et al., 1980). The composition of Francon quarry sabinaite reported as [Na.sub.2]O 20.7, CaO 0.2, Zr[O.sub.2] 39.1, Hf[O.sub.2] 0.47, Ti[O.sub.2] 12.0, C[O.sub.2] 27.1, total 99.57 weight %, is not significantly different from the composition of sabinaite from Mont Saint-Hilaire. Sabinaite crystals from the Francon quarry are tabular on (001) with dominant {001} basal pinacoid, bounded by {100} and {110} prisms, similar to sabinaite from Mont Saint-Hilaire. Individual plates are optically colorless and the luster varies from vitreous to silky. No fluorescence is observed under ultraviolet radiation (Jambor et al., 1980). Sabinaite is a late-stage mineral typically associated with calcite, dawsonite, gibbsite, quartz, cryolite, weloganite and many other cavity minerals. Due to its resemblance to other white, powdery coatings and aggregates, there is no reliable way to visually identify sabinaite.
Saponite ([Ca.sub.0.5]Na)[.sub.0.3](Mg,[Fe.sup.2+])[.sub.3](Si,Al)[.sub.4][O.sub.10](OH)[.sub.2]*4[H.sub.2]O
Saponite, a member of the smectite group, has been identified at the Canadian Museum of Nature as dull, opaque, beige, spherical aggregates in cavities in a Francon quarry dike. The X-ray diffraction pattern suggests that it is an aluminum-rich variety.
Serpentine series [Mg.sub.3][Si.sub.2][O.sub.5](OH)[.sub.4]
A chrysotile or lizardite member of the serpentine series has been found as a waxy, bluish gray to green, clay-like crust in a weathered dike in the alcove (A. P. Sabina, personal communication, 2004). Serpentine is a common alteration product of olivine in lamprophyric rocks such as camptonite.
Siderite [Fe.sup.2+]C[O.sub.3]
Siderite is a relatively common mineral in the lower sill cavities, and rare in the upper sill. It is found as transparent to translucent and opaque, pale yellow, greenish yellow, amber and brown rhombohedra, 1-2 mm across, sometimes lining cavities, and as botryoidal aggregates, commonly mixed with ankerite and dolomite. It is an intermediate-stage mineral, and has been observed on calcite (sometimes as an epitactic overgrowth), strontianite, dolomite and quartz. Other associated minerals include dawsonite, celestine, analcime, weloganite, cryolite, barite, goethite and hematite. In the upper sill it has been found in association with dresserite. Visual identification of Francon quarry siderite is
unreliable because of its resemblance to ankerite and dolomite.
Smythite [Fe.sub.9][S.sub.11]
Smythite is very rare in the upper and lower sill cavities as metallic, bronze-yellow to dark brown and almost black, thin, foil-like flakes and hexagonal crystals, typically less than 0.5 mm in diameter, and rosette-like aggregates. Some crystals have a ragged, irregular outline. Smythite is sometimes associated with pyrrhotite from which it is difficult to distinguish visually. Individual crystals of pyrrhotite are typically thicker and better formed. Other associated minerals include albite, analcime, barite, calcite, dawsonite, fluorite, quartz, siderite and strontianite.
Sphalerite (Zn,Fe)S
A relatively common and wide-spread mineral at the Francon quarry, sphalerite is found in very small concentrations, most commonly associated with dawsonite and fluorite. It occurs as sharp, vitreous to adamantine, transparent to translucent, orange-yellow, orange, reddish brown, and black crystals, up to 5 mm in diameter. Crystals are modified {111} tetrahedra, almost invariably contact-twinned on (111), and often flattened; some crystal faces are selectively frosted. Sphalerite is also found as yellow, spherical aggregates composed of rounded plates 1-2 mm in diameter, and as orange, platy aggregates of tiny crystals. The latter were found as a second-generation overgrowth on black and brown sphalerite crystals. Sphalerite has also been observed as pink to reddish botryoidal aggregates associated with natrojarosite. After dawsonite and fluorite, the most common associated minerals in the sill cavities are calcite, strontianite, galena, pyrite and marcasite. Sphalerite has also been found as orange-brown granular patches in the sill rock, and as yellow resinous masses in the limestone.
Strontianite SrC[O.sub.3]
Strontianite is very common at the Francon quarry, especially in cavities in the upper sill, and is found in a great variety of crystal habits and aggregate types. It occurs as translucent to opaque, white to pale yellow and beige, generally smooth-surfaced spheroids, hemispheres and compact spherical and botryoidal aggregates up to 10 cm in diameter. It also forms translucent to opaque, white to pale beige spheres consisting of numerous, radiating, acicular crystals with sharp acute terminations, typically 1-10 mm in diameter. It is also found as colorless to white and pale yellow tufts, parallel bundles, and sheaf-like clusters of fibrous to acicular crystals, and as white, finely granular, porcelaneous and waxy globular aggregates.
Strontianite crystals occur in three general habits: tabular, blocky and columnar, all bound by essentially the same forms; the {010} pinacoid, dominant in the tabular and prominent in both the columnar and blocky habits; the {110} prism, dominant in the columnar, prominent in the tabular and minor in the blocky habits; the {001} basal pinacoid is dominant in the blocky and minor in the other habits; and the {011} and {021} prisms and {111} dipyramids are relatively minor forms. Practically all strontianite crystals are contact-twinned on (110), and this results in a variety of interesting twinned groups and aggregates. Particularly attractive are transparent, pale pink, columnar to tabular sixling twins up to 1 cm in diameter, sometimes forming rosette-like groups. Also fairly common are peculiar aggregates of stacked, stellate sixling twins consisting of transparent, pale yellow, tabular crystals. Strontianite has also been found as radiating, spray-like aggregates up to 5 cm long, consisting of colorless to pale yellow, elongated columnar groups, with hexagonal cross-section and shallow grooves parallel to [001] indicative of contact twinning.
Strontianite is a late-stage mineral in the sill cavities, sometimes found as multiple generations. Well-formed individual crystals are far less common than the various types of aggregates. The associated minerals include practically all the cavity minerals. Strontianite also occurs as solid masses completely filling small cavities in the sill rock, and as colorless, tabular crystals and spherical groups of acicular crystals in limestone cavities.
Strontianite fluoresces a bright yellowish white under short-wave, medium-wave and longwave ultraviolet radiation, and phosphoresces a strong, medium-duration, yellowish white after exposure to all three wavelengths.
Strontiodresserite (Sr,Ca)[Al.sub.2](C[O.sub.3])[.sub.2](OH)[.sub.4]*[H.sub.2]O
Strontiodresserite, the strontium-dominant analog of dresserite with Sr + Ca > Ba, was described from the Francon quarry as a new species in 1977 (Jambor et al., 1977). It was recognized as a potentially new species during the original investigation of Francon quarry minerals and designated as APS No. 6 (Sabina, 1976). The infrared characteristics of strontiodresserite were investigated by Farrell (1977), and the space group was determined by Roberts (1978). Its crystal structure has not been solved to date, nor is there a complete quantitative analysis. The molar proportions of C[O.sub.2], [H.sub.2]O and OH in the theoretical formula are based on the similarity of its X-ray diffraction powder pattern to dundasite, with which it is considered to be isostructural (Roberts, 1978).
Very recently, strontiodresserite has also been found in a marble quarry near Kjopsvik, Tysfjord, Nordland, Norway, where it occurs as white, fibrous masses of capillary crystals up to 2 cm long (T. Andersen, personal communication, 2004), and in middle Jurassic marl at Condorcet, Drome, France (Martin et al., 2004). In the latter locality, which has yielded the richest and best specimens, strontiodresserite occurs in fissures as compact, spherical aggregates, less than 2 mm in diameter, of radiating, silky white, fibrous crystals. It is interesting to note that the three known occurrences of strontiodresserite are in totally different geological environments, in igneous rock in the Francon quarry, metamorphic rock in Norway and sedimentary rock in France.
Strontiodresserite is considerably rarer than dresserite or hydrodresserite, and known to occur only in the upper sill, as spherical aggregates up to 1 mm in diameter, consisting of radiating, silky white, flattened fibers, 0.1-0.5 mm long. Some of the larger spheres have a very smooth surface with a waxy to vitreous luster. Jambor et al. (1977) described strontiodresserite as occurring as "vitreous to silky white coatings, some of which are atoll-shaped" and "extremely fine-grained lath-like grains of maximum dimensions 0.1 X 0.01 X 0.001 mm." However, later finds revealed larger spheroids. These yielded larger crystal fibers which enabled the determination of the space group (Roberts, 1978). Individual crystals are colorless and morphologically similar to dresserite, very thin and bladed, elongated on [001] and flattened on (010). However, to date, no crystals suitable for goniometric measurements have been found.
In some of the best specimens, strontiodresserite occurs as spherical groups embedded in powdery masses of montroyalite. Other associated minerals are albite, quartz, weloganite and dawsonite. Although the smooth-surfaced spheres are fairly distinctive, visual identification of strontiodresserite is unreliable. Energy-dispersive spectroscopy, however, can readily identify the mineral. Yellowish white fluorescence under both shortwave and longwave ultraviolet radiation is reported for the cotype specimen ROM M344626 (R. A. Ramik, personal communication, 2004), but could not be confirmed by the authors, nor was it reported in the original description by Jambor et al. (1977).
Sulfur S
Sulfur is found very rarely as an alteration product of marcasite and pyrite, commonly associated with natrojarosite, rozenite and halotrichite. It forms black, sooty to earthy coatings, and yellow powdery coatings and aggregates on oxidized marcasite and pyrite.
Synchysite-(Ce) Ca(Ce,La)(C[O.sub.3])[.sub.2]F
Synchysite-(Ce) is the most common of the few known rare-earth element minerals found in the quarry. It occurs very rarely in both the upper and lower sills, and in the dikes, as white, silky spherules up to 1 mm in diameter, and as silky white, gray to tan, fibrous, flaky or powdery aggregates associated with marcasite, celestine and barite (Sabina, 1976). It is also found as gray, greenish gray and brown, sharp hexagonal plates 0.5-1 mm in diameter, forming rosette-like groups; as silvery gray flakes, sometimes stained orange, forming rounded plates and spherules 0.5-1 mm in diameter; and as sprays, 4-5 mm long, composed of aggregates of minute, silvery flakes, that may be pseudomorphs after a fibrous or acicular precursor. Associated minerals include quartz, fluorite, dawsonite, marcasite, pyrite, mordenite and calcite.
Talc [Mg.sub.3][Si.sub.4][O.sub.10](OH)[.sub.2]
Talc occurs as white patches associated with a serpentine-series mineral in a highly weathered dike in the alcove (A. P. Sabina, personal communication, 2004).
Thaumasite [Ca.sub.6][Si.sub.2](C[O.sub.3])[.sub.2](S[O.sub.4])[.sub.2](OH)[.sub.12]*24[H.sub.2]O
Thaumasite has been found as a white, micro-fibrous, crackled crust, several square centimeters in area, on fracture surfaces in a highly weathered serpentine-bearing dike in the alcove (GSC APS 724 and 730).
Thenardite [Na.sub.2]S[O.sub.4]
A supergene species, thenardite has been observed as a thin, white, powdery efflorescence on fracture surfaces in sill rock and limestone at the upper sill-limestone contact.
Thorbastnasite Th(Ca,Ce)(C[O.sub.3])[.sub.2][F.sub.2]*3[H.sub.2]O
Thorbastnasite occurs, very rarely, in the lower sill cavities as silky to waxy, white spherules and hemispheres to 750 [micro]m in diameter, composed of radiating fibers, and as coatings of fibrous aggregates, associated with baddeleyite and zircon (Sabina, 1979). It has also been found as stringers of very tiny white spherules associated with fluorite, calcite, quartz and dawsonite; as pearly to waxy, opaque white spherules up to 0.5 mm in diameter; and as irregular aggregates up to 5 mm across, composed of minute flakes partially overgrown by hematite and associated with fluorite, dawsonite, ankerite, celestine, goethite and calcite. Thorbastnasite also occurs admixed with fluorite as velvety black rounded aggregates associated with calcite and dawsonite. Thorbastnasite is visually indistinguishable from the many other white spherules found in the quarry.
Viitaniemiite NaCaAl(P[O.sub.4])([F.sub.1]OH)[.sub.3]
Viitaniemiite was described as a new species from the Viitaniemi pegmatite, Erajarvi area, Orivesi, Etela-Suomen Laani, Finland, where it occurs as sprays of bladed crystals up to 3 cm long (Lahti, 1981). Its crystal structure was solved by Pajunen and Lahti (1984). The Francon quarry is the second known locality for the species (Ramik et al., 1983). Interestingly, it was collected at Francon in 1976, before its description from Finland, but it was not immediately recognized as a potential new species. Viitaniemiite has also been reported from Paprok, Afghanistan, where outstanding crystals up to 18 cm long have been found (Weerth, 1992), and from Greifenstein, Ehrenfriedersdorf, Erzgebirge, Saxony, Germany (Spallek, 1996).
At the Francon quarry, viitaniemiite is exceedingly rare, known only from a few specimens collected in 1976 from a block of rock from the upper sill on the quarry floor near the northeast wall (Ramik, 1992). It was found in cavities as delicate sprays of vitreous, colorless, slightly tapering, bladed crystals, and as solitary crystals up to 2 X 0.5 X 0.2 mm. The crystals are elongated along [010] and flattened on (100), and show dominant {100} and poorly defined {001} faces, with indistinct terminations in the [010] zone. On a microscopic level, the crystals are invariably twinned by reflection on the (100) plane. In contrast to viitaniemiite from the type locality, viitaniemiite from Francon is manganese-free, with the composition [Na.sub.2]O 11.4, [Al.sub.2][O.sub.3] 23.4, [P.sub.2][O.sub.5] 28.1, CaO 22.3, MgO 0.1, F 14.5, O = F-6.1, total 93.7 weight %, [H.sub.2]O not determined or calculated, resulting in the empirical formula [Na.sub.0.91]([Ca.sub.0.98][Mg.sub.0.01])[.sub.[summation]0.99][Al.sub.1.13]([P.sub.0.98][O.sub.4])[F.sub.2](OH), or ideally NaCaAl(P[O.sub.4])-[F.sub.2](OH). Ramik et al. (1983) concluded that the Francon mineral was therefore the Ca end-member in terms of the "Ca-Mn diadochy."
Viitaniiemite was the first phosphate mineral reported from the sill cavities. It is associated with colorless cryolite, calcite, weloganite, and minor dawsonite, fluorite, dresserite, pyrite, quartz and galena. Paragenetically, viitaniemiite precedes cryolite, fluorite and pyrite. Although the elongated, tapering crystals of viitaniemiite are distinctive, their small size and transparency make them easy to overlook.
Voggite [Na.sub.2]Zr(P[O.sub.4])(C[O.sub.3])(OH)*2[H.sub.2]O
Voggite is the tenth and most recent new species described from the Francon quarry (Roberts et al., 1990). It was found in amygdaloidal cavities in a basaltic dike that intersects the upper sill in the alcove. The crystal structure was solved by Szymanski and Roberts (1990). Because the thin, acicular to fibrous crystals of voggite rapidly decompose under an electron beam, conventional microprobe analysis was only partly successful, and the ideal chemical composition was therefore derived from the crystal structure data: [Na.sub.2]O 17.95, Zr[O.sub.2] 35.69, [P.sub.2][O.sub.5] 20.56, C[O.sub.2] 12.75, [H.sub.2]O 13.05, total 100.00 weight %. The Francon quarry is currently the only known locality for the species.
Voggite is exceedingly rare and known only from a few specimens collected in 1985, first by Adolf Vogg, a mineral collector for whom the mineral was named. After an initial X-ray diffraction analysis it was immediately recognized as a potentially new species and designated as APS No. 15. The voggite-bearing dike, actually an offset of a basaltic sill, was exposed in the northeast face of the alcove near the bottom of the ramp (Ramik, 1992; A. P. Sabina, personal communication, 2005). Although amygdules are distributed throughout the dike, those containing voggite are localized within a few centimeters of the contact between the dike and the phonolite sill. This suggested that the mineral was the result of reaction between the intruding dike magma and the sill which was the source of zirconium (Roberts et al., 1990).
Voggite occurs in cavities within amygdules 1-3 mm across, as matted nests and irregular aggregates of vitreous, colorless to white, acicular capillary crystals rarely exceeding 1 mm in length and 6-8 [micro]m in diameter. The crystals are elongated along [010], with an aspect ratio of about 100:1, and display the following forms: major {100} and {[bar.1]01} pinacoids, and minor {001} pinacoid. The terminal faces in the [010] zone are indistinct. It is directly associated with quartz, calcite and dawsonite. Other amygdules in the dike contain mordenite, dachiardite-Na, a garronite-like mineral, analcime, calcite, dolomite, barite and fluorite, often as solid fillings. Voggite superficially resembles the associated fibrous to eapillary mordenite, however its brittleness and unbent crystals may be helpful in distinguishing it from the flexible mordenite. Voggite does not fluoresce under ultraviolet radiation.
Weloganite [Sr.sub.3][Na.sub.2]Zr(C[O.sub.3])[.sub.6]*3[H.sub.2]O
The discovery of what proved to be a new species, weloganite, by GSC mineralogist Ann Sabina on her first visit to the quarry in 1966, was the pivotal event that established the Francon quarry as a major mineral locality. It is very rare that a new mineral is discovered as large, attractive crystals, as was the case with weloganite. Not only did weloganite occur as multi-centimeter crystals, but it was extraordinarily abundant in the quarry. Fittingly, the mineral honors Sir William E. Logan (1798-1875), the Montreal-born founding director of the Geological Survey of Canada. The Francon quarry is only a few kilometers from the site of the first headquarters of the Geological Survey, and the site of the Logan farm, Sir William's birthplace.
Originally designated as APS No. 1, weloganite was described as a new species, and the first zirconium-bearing carbonate, by Sabina et al. in 1968. However, it proved to be a problematic species both structurally and chemically. Sabina et al. (1968) concluded that, based on single-crystal X-ray precession photographs, weloganite was trigonal. Subsequently, Gait and Grice (1971) postulated the existence of a monoclinic polytype. Chen and Chao (1975) showed that weloganite was triclinic, with a pronounced rhombohedral sub-cell which resulted in a pseudotrigonal symmetry. They also showed the existence of a pseudomonoclinic cell which accounted for the monoclinic symmetry suggested by Gait and Grice (1971). The crystal structure of weloganite was finally solved by Grice and Perrault (1975). They confirmed that weloganite was triclinic and very strongly pseudotrigonal. As discussed below, the trigonal pseudosymmetry is very apparent in the morphology of weloganite crystals. Weloganite is isostructural with triclinic donnayite-(Y), the Y-analog of weloganite (Chao et al., 1978), which exists as both trigonal and triclinic polytypes (Trinh Thi Le Thu et al., 1992; Khomyakov, 1995). Weloganite is also structurally related to mckelveyite-(Y), ewaldite, and the two unnamed carbonates UK33A and UK37A from Mont Saint-Hilaire (McDonald, 1989; Chao et al., 1990).
The composition of weloganite was originally reported as SrO 41.0, Zr[O.sub.2] 19.4, C[O.sub.2] 32.2, [H.sub.2]O 6.6, total 99.2 weight %, with the theoretical formula [Sr.sub.3][Zr.sub.2][C.sub.9][H.sub.8][O.sub.31] (Sabina et al., 1968). Although weloganite was recognized to be a carbonate, the results of infrared and DTA analyses were ambiguous as to the structural units present. Gait and Grice (1971) subsequently showed that weloganite contained very significant amounts of both Na and Ca. The composition reported by Grice and Perrault (1975) and used in their structure determination is SrO 36.18, CaO 1.14, Zr[O.sub.2] 15.26, [Na.sub.2]O 7.75, [K.sub.2]O 0.02, C[O.sub.2] 30.7, [H.sub.2]O 7.85, Si[O.sub.2] 0.25, MgO <0.02, [Fe.sub.2][O.sub.3] 0.03, total 99.2 weight %, resulting in the now accepted formula [Sr.sub.3][Na.sub.2]Zr(C[O.sub.3])[.sub.6]*3[H.sub.2]O.
Weloganite has also been found, rarely and in very minor quantities, at two other Monteregian alkaline province localities in the Montreal area. The first of these occurrences is in an alkaline sill in the Lafarge (Montreal-Est) quarry--also known in the past as Francon (Montreal-Est) quarry)--8 km northeast of the Francon quarry. The other is in a nepheline syenite pegmatite in the Poudrette quarry at Mont Saint-Hilaire (Horvath and Gault, 1990). At the Lafarge (Montreal-Est) quarry, weloganite occurs, very rarely, as well-formed, yellow crystals up to 3 mm, and at Mont Saint-Hilaire as 1-2 mm irregular, glassy fragments, in the cores of donnayite-(Y) crystals, intimately associated with UK33A (Chao et al., 1990), an unnamed carbonate which may be the Cedominant analog of donnayite-(Y).
In the Francon quarry, weloganite occurs in both the upper and lower sills. The crystals are generally larger, more abundant and more evenly distributed in the upper sill, at least in the zones documented in the period of 1968-1985, whereas in the lower sill the concentration of weloganite is more localized. However, crystals found on the lower level are more varied in habit, generally more transparent, and lack the coatings and encrustations by other minerals that are common in the upper sill.
Weloganite is most often transparent to translucent, pale yellow to lemon-yellow, orange-yellow and amber. Opaque white, gray and greenish gray crystals are also common. Less commonly, weloganite is colorless and, rarely, pale green or pink. The luster ranges from adamantine on some faces, to vitreous, greasy and dull. Color zoning along and transverse to the c-axis is quite common, with the zones varying not only in color but also in transparency. Basal sections of larger weloganite crystals may show a yellow, equilateral triangular core, surrounded by a colorless zone followed by concentric, opaque white and colorless, thin hexagonal bands at the outer face. This type of zoning is analogous to that observed in liddicoatite crystals from Madagascar, and reflects a change in crystal growth from a dominant pseudo-trigonal pyramidal form to a prismatic form, perhaps with an interruption as evidenced by the presence of very fine-grained pyrite at the boundary of the triangular core in some crystals (Chen and Chao, 1975). Further evidence of interrupted growth is seen in some larger crystals in which a white outer shell is readily separated, sometimes naturally, to reveal a yellow core crystal with lustrous faces.
The reason for the color change itself is unknown. Sabina et al. (1968) conducted an electron microprobe traverse of zoned grains of weloganite and found no variation in the Sr, Zr, Ba and Ca concentrations across the zones. Chen and Chao (1975) noted some differences in optical properties between the core and the rim of a zoned crystal but found that the X-ray powder diffraction patterns were identical.
Weloganite crystals (5) are characteristically strongly striated or grooved due to pronounced oscillatory growth along [001], and most are distinctly hemimorphic. Twinning is common, as evidenced by prominent re-entrant angles along [001], and sharp angular articulations, or kinks, in smaller (less than 1 cm) weloganite crystals. The twin law involved is a 120[degrees] rotation about the reciprocal axis [001]* with (001) as the twin plane; or in triclinic terms, a 120[degrees] rotation about [103] (Chen and Chao, 1975).
What appear to be conspecific epitactic overgrowths of weloganite on weloganite have been observed, with second-generation small crystals overgrowing larger crystals on the {001} pedion, and more rarely on prism faces, occasionally as belt-like clusters of parallel crystals. The weloganite crystals in some cavities are corroded, with dissolution often having occurred preferentially on {001} and, in color-zoned crystals, along the interface between color zones. On the laminar remnants of the partially dissolved crystals, thin layers of powdery baddeleyite have been observed (see baddeleyite description).
Crystals of weloganite display a remarkable range of habits:
Habit A consists of barrel-shaped or hourglass-shaped, distinctly hemimorphic crystals with a hexagonal cross-section, elongated parallel to the c-axis, and ranging from 5 mm to, exceptionally, 6.5 cm in length. Crystal sizes up to 11 cm have been reported, but these were crystal aggregates rather than individual crystals. The crystals are usually terminated by variously developed {001} or {00[bar.1]} pedions. In some crystals the pedion termination is the base of what looks like an inverted pyramid (Fig. 86A). The crystals are bounded by pseudo-trigonal pyramids. Sabina et al. (1968) described them as {10l} and {01l} but other forms are plausible based on the strongest X-ray diffraction reflections of weloganite. Faces of the pseudo-trigonal prisms {100} and {010} may also be present. Crystals of habit A are yellow, yellowish white and white, and commonly color-zoned. This is the most common and wide-spread habit in the upper still, and has yielded the largest crystals, and spectacular complex aggregates up to 10 cm long. Some of the large crystals were found loose in the cavities, and many were "floaters," some doubly terminated and without any obvious point of attachment. The aggregates consist of many crystals in a parallel or possibly epitactic arrangement on a large core crystal, producing intricate multi-crystal groups. Habit A crystals are commonly coated or encrusted by other minerals, mostly dull white, thin layers of gibbsite and doyleite, and very rarely spherules of franconite. Associations include dresserite, hydrodresserite, dawsonite, quartz, calcite, strontianite and marcasite.
Habit B is characterized by tapering hemimorphic crystals with a nearly triangular (trigonal) cross-section, with or without a very small triangular {001} pedion. The crystals are transparent to translucent, bright yellow, with a vitreous to adamantine luster, and range from 2 mm up to 2 cm in length. These include some of the sharpest, most transparent and most attractive crystals of weloganite, which were found in the lower sill, in the northern corner in the quarry. In some cavities the crystals show selectively etched zones and some are almost completely dissolved, with only a thin shell or skeletal remnant, some of which is pseudomorphous baddeleyite. Other associated minerals include barite, quartz, fluorite, dolomite, dawsonite, celestine, hematite, goethite and colorless cryolite.
Habit C crystals are hemimorphic and pseudo-trigonal pyramidal with a hexagonal or nearly trigonal cross-section, and dominant {001} pedions. The crystals are colorless, transparent and pale yellow; or translucent greenish gray, with a vitreous luster; or opaque white with a waxy to dull luster. Typically, they form complex cone-shaped aggregates 2-8 mm across consisting of many intergrown crystals. The crystals were found in the lower sill associated with calcite, pyrite, dawsonite and quartz.
Habit D is characterized by tabular crystals with a hexagonal cross-section, and dominant {001} and {00[bar.1]} pedions. The crystals are up to 8 mm in diameter. They are translucent to opaque, gray and white. This is a very rare habit, observed only in the lower sill in association with yellow cryolite, barite, elpidite, strontianite and synchysite-(Ce).
Habit E crystals are very sharp, complex and hemimorphic, consisting of a column with hexagonal cross-section, capped by a pyramidal, habit C crystal, often resulting in a funnel-like shape, with a well-developed {001} pedion. In some crystals the columnar sections display peculiar kinks or angular articulations which may be the result of twinning. Other crystals are bifurcated into two individuals. The crystals are colorless to transparent pale yellow, with a vitreous to subadamantine luster, 2-10 mm long, and are found in the lower sill associated with analcime, ankerite, barite, calcite, strontianite and marcasite.
Habit F crystals are columnar, resembling hexagonal prisms, terminated by {001} and {00[bar.1]} pedions. The colorless to transparent, pale-yellow crystals, 2-6 mm long, are very sharp, have a vitreous luster and show no striations. These were exclusively found in the lower sill. Associated minerals include analcime, barite and pyrite. Of all the observed habits, these, and habit G most closely allude to the true triclinic symmetry of weloganite.
Habit G is characterized by short blocky crystals, 2-5 mm across, with a rhombic cross-section, resembling simple rhombohedra. The crystals are opaque white with a dull luster and without striations, and were found only in the lower sill. Associated minerals include albite, brookite, quartz (pseudomorphic after natrolite), cryolite, dawsonite, marcasite and natrolite.
In the paragenetic sequence, two generations of weloganite are observed in the sill cavities: an early to intermediate-stage, and an intermediate to late-stage generation.
Weloganite is fluorescent, giving a medium-intensity, orange response under shortwave radiation, greenish yellow under mediumwave and weak orange-brown under longwave ultraviolet radiation. The mineral is also pyroelectric (R. A. Ramik, personal communication, 2004), and triboluminescent as evidenced by the emission of bluish-white flashes of visible light when crystals are mechanically fractured or crushed (Gait and Grice, 1971).
A few gemstones have been cut from Francon weloganite. Three pale yellow stones, with inclusions (a 0.52-carat curved rectangular cut, a 0.74-carat oval cut, and a 4.27-carat calf's head cut) and a transparent yellow 0.12-carat tapered baguette are in the collection of the Canadian Museum of Nature (W. Wight, personal communication, 2004).
Wurtzite (Zn,Fe)S
Wurtzite is known from the Francon quarry as a single specimen from the lower sill, with a dark brown, incomplete, hemimorphic crystal less than 2 mm across, associated with quartz, calcite and barite (GSC APS 721-1).
Zircon ZrSi[O.sub.4]
Zircon is a rare accessory mineral in the lower and upper sill rock. It is also found as partially metamict crystals in cavities in the lower sill. Steacy and Jambor (1969) and Jambor et al. (1976) reported the presence of zircon "as disseminated, euhedral to subhedral crystals, up to a millimeter in length." In the lower sill cavities it occurs as gray, tan and cream-colored, plate-like and sheet-like granular aggregates (Sabina, 1979), and as vitreous, yellow granular crusts on weloganite (Sabina, 1976); the partially metamict crystals are yellow, tan, amber and gray, dull to waxy, aggregates (Sabina, 1979), and the metamict material also forms a silky, white coating on analcime (GSC APS 559a). From the lower sill rock, Sabina (1979) reported "pink, yellow, amber, brown and gray euhedral grains." The authors have found embedded, vitreous, transparent to translucent, pale pinkish brown and pale brown, sharp to somewhat rounded dipyramidal crystals and short tetragonal prisms up 2 mm long, as well as dull to resinous, opaque, dark brown, elongated crude crystals, exceptionally up to 1 cm long. The crystals have simple morphology, consisting of either the {111} dipyramids only, or the combination of {100} prism and the {111} dipyramids. Well-formed crystals are rare.
"Bitumen"
Minerals in the sill cavities, especially in the upper sill, are sometimes partially or wholly coated by a brittle, transparent to opaque, amber to brown or black film or crust of a hydrocarbon of unknown composition (Sabina, 1979). Under high magnification (SEM) the crusts have a ridged and corrugated appearance. The crusts can often be easily removed in order to reveal the underlying minerals.
ACKNOWLEDGMENTS
For most of the specimen-producing life of the Francon quarry, from its discovery as a mineral locality in 1966 to its closing in 1985, the persistence and dedication of one individual. Ann P. Sabina of the Geological Survey of Canada, stands out. We take pleasure in dedicating this paper to her in acknowledgment of her tremendous contribution to the mineralogy of the quarry. We are also grateful for her generous assistance with mineral identifications over a period of many years, for sharing much unpublished information on the quarry and its minerals, and for providing numerous photographs for our use. We also wish to thank Andrew Roberts of the Geological Survey of Canada, Ralph Rowe of the Canadian Museum of Nature, and Dr. George Chao formerly of Carleton University, for X-ray diffraction analyses; Robert Gault of the Canadian Museum of Nature for SEM work and microprobe analyses; Dr. Richard Herd for granting access to the National Mineral Collection at the Geological Survey of Canada and for providing copies of the descriptive lists of the Francon quarry mineral suite assembled by Ann Sabina; Michel Picard of the Canadian Museum of Nature for providing access to the National Mineral Collection at the Canadian Museum of Nature; Dr. Donald Doell for the generous loan of a suite of Francon quarry specimens for study and photography; Jacques Poulin for expert assistance and equipment in investigating the response of Francon quarry minerals to ultraviolet radiation; Dr. David Dolejs, formerly of McGill University, for a petrographic examination of dike rocks from the Francon quarry; Joan Kaylor of the Redpath Museum, McGill University, for the loan of Francon quarry specimens for photography; Dr. Joel Grice of the Canadian Museum of Nature and Dr. Jeanne Paquette of McGill University for helpful discussion on the morphology of weloganite; Robert Ramik of the Royal Ontario Museum for information on the occurrences of voggite and viitaniemiite; Janet and Stephen Cares for information on analyzed Francon quarry specimens in the Cares mineral collection; Willow Wight for information on Francon quarry gemstones; Garry Glenn (now deceased) for permission to reprint his line-drawings of specimens; Dr. Joseph Mandarino for providing draft copies of the Francon quarry type mineral descriptions in The International Encyclopedia of Minerals; Dr. Nicolas Meisser of the Musee Cantonal de Geologie, Lausanne, Switzerland for providing data and documentation on the recent find of strontiodresserite in France; and Serge Perreault, geologue resident of the Ministere des Ressources naturelles of Quebec for arranging and accompanying the authors on a 2003 geological excursion to the quarry. We also acknowledge the following people who helped in various ways: T. Anderson, Albert Cornu, Donald Doell Jr., Dr. Igor Pekov, and Tony Steede. The manuscript was reviewed by Andrew Roberts and Ann Sabina whom we thank for their helpful comments. Special thanks to Dr. Wendell Wilson for his great editorial work. Finally, on behalf of the mineral collecting community, we wish to express our appreciation to the management of Francon (1966) Limitee, former division of Lafarge Canada Inc., who generously provided access to the Francon quarry over a period of nearly two decades.
BIBLIOGRAPHY
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Peter Tarassoff
91 Lakeshore Road
Beaconsfield, Quebec, Canada H9W 4H8
Laszlo Horvath and Elsa Pfenninger-Horvath
594 Main Road
Hudson, Quebec, Canada J0P 1H0
(1) This quarry is also referred to as the Canada Cement quarry in older literature.
(2) The age cited by Simpson (1980) is for a carbonatite dike in another quarry also called the Francon quarry and located at Blackburn Hamlet near Ottawa, Ontario (K. L. Currie, personal communication, 2003).
(3) Fine specimens of calcite and dolomite have been found in Beekmantown Group dolomitic limestones in quarries off the Island of Montreal. In the stratigraphic column the Beekmantown Group lies below the Chazy Group and is not exposed in the Francon quarry.
(4) Jambor et al. (1980) reported that F-bearing gibbsite fluoresced and phosphoresced "bluish-white ('short' rays) and cream-white ('long' rays)."
(5) The morphology of weloganite crystals is described here in pseudo-trigonal rather than triclinic terms.
Table 1. Chemical analyses of upper sill rock, Francon quarry.
A B C D E F
Si[O.sub.2] (%)* 45.50 49.80 44.70 47.90 48.90 --
[Al.sub.2][O.sub.3] 19.70 20.10 18.60 20.20 21.70 --
[Na.sub.2]O 8.60 8.60 8.40 8.90 9.80 --
[K.sub.2]O 4.20 3.90 4.10 4.50 3.50 --
CaO 2.50 2.40 2.10 2.10 2.00 --
FeO 2.00 2.40 1.60 1.30 1.00 --
[Fe.sub.2][O.sub.3] 0.20 0.10 0.80 1.00 1.10 --
MgO 0.80 1.00 1.20 0.70 0.90 --
MnO 0.25 0.26 0.24 0.25 0.27 --
SrO 0.05 0.21 0.26 0.17 0.16 0.14
BaO 0.18 0.20 0.21 0.19 0.20 --
Ti[O.sub.2] 0.27 0.35 0.29 0.36 0.26 0.31
Zr[O.sub.2] 0.06 0.14 0.16 0.10 0.17 0.09
[Nb.sub.2][O.sub.5] 0.12 0.13 0.09 0.14 0.15 --
[P.sub.2][O.sub.5] 0.12 0.14 0.11 0.11 0.10 --
C[O.sub.2] 11.00 7.80 12.70 6.30 2.90 --
[H.sub.2]O 3.50 2.00 3.60 4.70 5.30 --
Total 99.05 99.53 99.16 98.92 98.41 --
[([Na.sub.2]O + [K.sub.2]O)**]/ 0.95 0.91 0.98 0.97 0.92 --
[[Al.sub.2][O.sub.3]]
*Weight per cent; **Agpaicity index. Molecular ratio.
A -- Gray rock, central part of sill, southwest face, near alcove
(sample F-9, Jambor et al., 1976).
B -- Light part of mottled sill rock near contact, northwest face
(sample F-21W, Jambor et al., 1976).
C -- Dark part of mottled sill rock near contact, northwest face (sample
F-21D, Jambor et al., 1976).
D -- Greenish sill rock containing aegirine-augite, northeast face
(sample F-32, Jambor et al., 1976).
E -- Greenish sill rock containing aegirine-augite, southeast face
(sample F-39, Jambor et al., 1976).
F -- Average of 39 samples from the entire perimeter of the quarry
(Steacy & Jambor, 1969; Jambor et al., 1976).
Table 2. Distribution and rarity of minerals in the Francon quarry.
Phonolite sills
Cavities Sill Dikes* Lime
Mineral Quarry Upper Lower Rock Cavities Rock stone
Aegirine R R
Albite C VC C
Almandine VR VR
Amphibole group C VC
Analcime C R VC VR R
Anatase VR VR VR VR
Ankerite C C R
Apatite group VR R VR R
Baddeleyite VR ER VR
Barite C R C VR
Bastnasite series ER ER
Biotite group VR ER VR C
Brookite R R R
Calcite VC VC VC C R VC
Celestine C R VC VR
Cerussite ER ER
Chromite ER ER
Cristobalite R R VR
Crocoite ER ER
Cryolite R R R
Dachiardite-Na ER ER ER
Dawsonite VC VC VC VC VR
Dickite ER ER
Dolomite R VR R R C
Doyleite VR VR VR
Dresserite C C
Elpidite VR VR
Fluorite VC C VC ER R
Franconite ER ER
Galena R R R
Garronite-like m. ER ER
Gibbsite-like m. C C C
Gismondine ER ER
Glauconite series ER ER
Gmelinite series ER ER
Goethite R C
Graphite ER ER?
Gypsum VR VR
Halite ER ? ? ER
Halloysite VR VR VR VR
Halotrichite VR VR VR
Harmotome ER ER
Hematite C C
Hochelagaite ER ER
Humboldtine ER ? ?
Hydrocerussite ER ER
Hydrodresserite C C
Ilmenorutile VR VR VR
Kaolinite R VR R
"K-feldspar" R R C R
Magnetite VR VR
Marcasite VC VC VC C
Molybdenite ER ER
Montmorillonite R R
Montroyalite ER ER
Mordenite VR VR VR
Nahcolite ER ? ? ER
Natrojarosite VR VR
Natrolite VR VR
Olivine group VR C
Paratacamite ER ER
Phillipsite series ER ER
Phlogopite VR ER VR
Pseudorutile VR VR VR
Pyrite C C C C C C
Pyrochlore VR ER? ER? VR
Pyrrhotite VR VR VR VR
Quartz VC VC VC C VR R
Rozenite VR VR VR
Rutile ER ? ?
Sabinaite VR VR
Saponite ER ER
Serpentine series ER C
Siderite R VR R
Smythite VR VR ER
Sphalerite C C C VR VR
Strontianite VC VC C VR C
Strontiodresserite VR VR
Sulfur VR VR VR
Synchysite-(Ce) VR VR VR ER
Talc ER VR
Thaumasite ER ER
Thenardite ER ER ER
Thorbastnasite ER ER
Viitaniemiite ER ER
Voggite ER ER
Weloganite VC VC VC
Wurtzite ER ER
Zircon VR ER VR
"Bitumen" C C ?
Legend: ER = extremely rare; VR = very rare; R = rare; C = common; VC =
very common; ? = distribution and/or rarity uncertain;
* includes minor sills
Table 3. Classified list of Francon quarry minerals.
Elements
Graphite
Sulfur
Sulfides
Galena
Marcasite
Molybdenite
Pyrite
Pyrrhoitite
Smythite
Sphalerite
Wurtzite
Halides
Cryolite
Fluorite
Halite
Oxides & hydroxides
Anatase
Baddeleyite
Brookite
Chromite
Cristobalite
DOYLEITE
FRANCONITE
Gibbsite-like mineral
Goethite
Hematite
HOCHELAGAITE
Ilmenorutile
Magnetite
Paratacamite
Pseudorutile
Pyrochlore
Quartz
Rutile
Carbonates
Ankerite
Bastnasite series
Calcite
Cerussite
Dawsonite
Dolomite
DRESSERITE
Hydrocerussite
HYDRODRESSERITE
MONTROYALITE
Nahcolite
SABINAITE
Siderite
Strontianite
STRONTIODRESSERITE
Synchysite-(Ce)
Thorbastnasite
WELOGANITE
Sulfates
Barite
Celestine
Crocoite
Gypsum
Halotrichite
Natrojarosite
Rozenite
Thenardite
Phosphates
Apatite group
Viitaniemiite
VOGGITE
Silicates
Aegirine
Albite
Almandine
Amphibole group
Analcime
Biotite series
Dachiardite-Na
Dickite
Elpidite
Garronite-like mineral
Gismondine
Glauconite series
Gmelinite series
Halloysite
Harmotome
Kaolinite
"K-feldspar"
Montmorillonite
Mordenite
Natrolite
Olivine group
Phillipsite series
Phlogopite
Saponite
Serpentine series
Talc
Thaumasite
Zircon
Organic minerals
"Bitumen"
Humboldtine
CAPITALIZED species are type minerals
Table 4. New species discovered in the Francon quarry.
Mineral Reference
Weloganite Sabina et al. (1968)
Dresserite Jambor et al. (1969)
Hydrodresserite Jambor et al. (1977)
Strontiodresserite Jambor et al. (1977)
Sabinaite Jambor et al. (1980)
Franconite Jambor et al. (1984)
Doyleite* Chao et al. (1985)
Hochelagaite* Jambor et al. (1986)
Montroyalite Roberts et al. (1986)
Voggite Roberts et al. (1990)
*Co-type locality with Mont Saint-Hilaire
Table 5. Fluorescent minerals of the Francon quarry.
Shortwave 254 nm
Fluorescence Phosphorescence
Minerals Color Intensity Color
Calcite I. red W
Calcite II. pink S
Cryolite I. creamy white S white
(yellow)
Cryolite II. white S white
(colorless)
Dachiardite-Na orangy white W
Dawsonite pale yellow M
Dresserite I. yellowish white S white
Dresserite II. pale yellow-white M white
Elpidite greenish yellow M
Gibbsite-like whitish yellow M white
Gypsum I. orange M
Gypsum II. whitish yellow M
Kaolinite whitish yellow M
Montroyalite yellow M
Mordenite whitish yellow W
Natrolite white W
Quartz orange M
Strontianite I. yellowish white S yellowish white
Strontiznite II. pinkish violet M
Strontianite III. greyish white M white
Weloganite I. pale orange M
Weloganite II. orange M
Shortwave 254 nm Medium-wave 312 nm
Phosphorescence Fluorescence
Minerals Intensity Duration Color Intensity
Calcite I. red S
Calcite II. bright pink S
Cryolite I. W S greenish yellow M
(yellow)
Cryolite II. W S
(colorless)
Dachiardite-Na orange W
Dawsonite pale yellow M
Dresserite I. M S yellowish white S
Dresserite II. M S pale yellow-white M
Elpidite
Gibbsite-like W S yellow M
Gypsum I. orange M
Gypsum II. whitish yellow M
Kaolinite yellow M
Montroyalite orange-yellow M
Mordenite pale yellow W
Natrolite white W
Quartz orange M
Strontianite I. M M yellowish white S
Strontiznite II. pinkish violet M
Strontianite III. M M greyish white M
Weloganite I.
Weloganite II. greenish yellow W
Medium-wave 312 nm Longwave 352 nm & 368 nm*
Phosphorescence Fluorescence
Intensity
Minerals Color Duration Color Intensity
Calcite I.
Calcite II.
Cryolite I. white W S brownish yellow W
(yellow)
Cryolite II.
(colorless)
Dachiardite-Na orangy brown W
Dawsonite pinkish yellow M & W*
Dresserite I. white M S greenish yellow S
Dresserite II. white M S pale yellow-white M
Elpidite
Gibbsite-like white W S whitish yellow M
Gypsum I. orange M
Gypsum II. whitish yellow M
Kaolinite whitish yellow M
Montroyalite orange-yellow M
Mordenite pinkish yellow W
Natrolite white W
Quartz orange M
Strontianite I. yellowish S+ M yellowish white S
white
Strontiznite II. greyish white & W & W*
green
Strontianite III. white M M greyish white M
Weloganite I.
Weloganite II. orange brown W
Longwave 352 nm & 368 nm*
Phosphorescence
Minerals Color Intensity Duration Comments
Calcite I.
Calcite II.
Cryolite I.
(yellow)
Cryolite II.
(colorless)
Dachiardite-Na
Dawsonite Very rare
reaction
Dresserite I. white M & W* S
Dresserite II. white M & W* S
Elpidite
Gibbsite-like
Gypsum I.
Gypsum II.
Kaolinite
Montroyalite Only one
examined
Mordenite
Natrolite
Quartz Rare reaction
Strontianite I. yellowish white S M
Strontiznite II.
Strontianite III. white W M
Weloganite I.
Weloganite II.
The above reactions were confirmed by the authors (LH & EPH part time)
and J. Poulin, on multiple specimens for most species, using identical
techniques and equipment under uniform conditions.
The following reactions were reported (R. A. Ramik, 2004, personal
communications) but could not be confirmed by the authors. Fluorescence
was not reported in the original species descriptions.
Hydrodresserite white W
Strontio-dresserite yellowish white M yellowish white M
Legend: Intensity: S = strong; M = medium; W = weak. Duration: S =
short; M = medium; L = long. Minerals: Weloganite I. & II. represent
different UV reactions.