Gemmology Canada - Special Issue
By Stephen Bertalan, A.G. (C.I.G.)
Return to Top C10H16O+H2S: Amber up to 2.5cm. are found in yellow colour with a greenish tinge and occasional plant inclusions along the Quesnel River near Quesnel. Nodules are found in shaly sandstone along the Peace River Canyon, and sizable nodules off the Pacific coast on Graham Island of the Queen Charlottes.
Return to Top Al2 SiO5+Fe: Chiastolite variety is common in the black schist of the hills of Armstrong.
Return to Top : A metamorphic rock formed from petilic sediments. This decorative material became renown because of the imaginative and skillful carvings of the Haida Indians of Skidegate and Massett, of the Queen Charlottes. Another source for Argillite is north of Horseshoe Bay.
Return to Top BaSO4+Ca,Sr: Facetable yellow crystals up to 11.5cm. long have been found in veins of fluorite at the Rock Candy mine Kennedy Creek near Grand Forks.
Return to Top Be3Al2Si6O18+Fe,Mn,Cr,V,Cs: Most beryls in B.C. are found in pegmatites, although occurrences are numerous, beryls are not exceedingly common. Beryls of the Logjam Creek, Horseranch Range, Dortatelle Creek in the Cassiar area are small, opaque, poorly formed crystals of bluish green colour. A few well formed pale bluish green beryls have been seen at Fort Graham in the Buttle Range. Beryls have been identified at the Bonanza mica mine near Tete Jaune Cache. Pegmatite dykes on Mt. Begbie also contain beryls. Pegmatite is abundant in large dykes and loose blocks in the Kootenay District. Most of beryls are very pale, near white with occasional blue-green crystals occurring in the Angus, Porcupine, White, Skookumchuk, and Hellroaring Creek areas. Recently pockets of pegmatite containing yellow to yellow-green to aqua coloured beryls have been found in the Slocan Valley.
Return to Top Al2O3+Fe,Ti,Cr: Corundum is found in metamorphosed rocks such as gneiss and schist. Gneiss and Schist formations in B.C. are known to exist at Kinbasket Lake, Kootenay Lake ,Vernon, and Prince Rupert areas. Gem quality sapphire pebbles of light green colour have been found in the Pend Oreille River. Rubies of minute grains have been found in some of the tributary creeks of the Tulameen River.
Return to Top C: Reports of microscopic crystals from chromite found on Olivine Mt. near Tulameen and also from Scottie Cr. and Bonaparte River near Ashcroft.
Return to Top : Feldspars are the most abundant minerals, classified in two main groups, the alkali series and the plagioclase series. There are 100 million tones of feldspar reserves in 22 documented occurrences in B.C. All these deposits are commercial grade and so far gem quality materials (such as Moonstone, Labradorite, and Sunstone) have not been reported.
Return to Top CaF2: Very fine crystals are found lining large cavities of openings as large as 3 to 4 feet across at the Rock Candy Mine near Grand Forks. Green is the most common colour, but purple and colourless varieties also occur. Other less noted areas are Whiteman Cr., Scuzzy Cr., Lumby, Hellroaring Cr., and Liard River Hot Springs.
Return to Top : Of the complex family of garnets only two species are reported to exist in B.C., Almandite and Andradite. Perfect, clear-red almandite crystals up to 3cm. in diameter occur in mica schist along the Stikine River. Andradite garnet in fair crystals, but not suitable for cutting is found on Texada Isl. in a recent study, 16 garnet occurrences in 7 large areas were recorded; Southern Shuswap-Nelson area, Shuswap Lake-Vernon-Okanagan area, Revelstoke-Frenchman Camp-Big Bend area, Canoe River-Valemount-Mica Cr. area, Aiken Lake-Mesilinka River area, Hope-Yale-Harrison Lake-Lytton area, and Prince Rupert-Skeena River-Douglas Channel area. Most of this garnet is high-quality commercial grade, suitable for lapping and grinding with minor amounts useful for cutting.
Return to Top : An apple-green, fine-grained, massive idocrase is found southeast of Skihist Mt. Some of the material is translucent and may be gem quality.
Return to Top Na2(AlSi3O10): this solid-solution of the Zeolite group forms as slender or acicular prismatic crystals. Except for its rarity, Natrolite is usually an uninteresting white colour (sometime colourless, gray, yellowish, reddish). It has only been reported occurring in the Ice River area south-east of Golden.
Return to Top Ca2(Mg,Fe)5(Si4O11)2(OH)2: Large commercial quantities of good quality nephrite occur in B.C., extending from the northern provincial boundary, southeastward to the lower region of the Fraser River. The nephrite occurs as small to very large boulders, some weighing more than 15 tons (one specimen was estimated to weigh 80 tons). The best quality (in terms of colour, and solidity) comes from the central to northern part of the province. Known sources of nephrite yielding commercial quantities are being mined in the Atlin Lake, McDame, Dease Lake, Wheaton Cr.- Turnagain River,
Mt. Ogden- Fort St. James areas. In 1970 a 23 ton boulder from the Mt. Ogden area, was exhibited outside the B.C. pavilion at Expo 70 in Osaka Japan.
Nephrite from the Bridge River- Fraser River area is highly variable, even within the same boulder. Vivid hues are rare, with predominant colours being dark green, grayish-green, olive, and yellow-green. Some material is so dark that it appears black, but true black has not been found.
Return to Top (volcanic glass): Black obsidian occurs in varying sizes north of Anahim Lake, on Anahim Peak and Ilgachuz Mountains.
Return to Top (peidot) Mg2SiO4-Fe2SiO4: Timothy Mt., east-northeast of Lac La Hache produces bombs from which excellent dark green stones weighing as much as 10 carats have been obtained. Lightning Peak in the Monashee Mountains produces peridot grains large enough to cut small gems from.
Return to Top SiO2-nH2O: Common opal occurs in seams of rock outcroppings north of Princeton, and also in tertiary rocks at Savona Mt., Agate Mt., Horse Fly River,
Fourmile Cr., and Slocan Lake. Good quality hyolite is found near Hihum Lake and the Bonaparte River. Along the banks of the Deadman Cr., fire opal has been found. Well-grained opalized wood in black, brown, white, and green hues have been found along Barnes Creek near Ashcroft. Precious opal occurs only in a few locations in B.C.
The Eagle Creek deposits near Burns Lake Have been set aside for rockhounders. Milky coloured opals with only small portions displaying a red and green play of colour have been found on an unnamed mountain west of Penticton.
Most recently several interests are attempting to engage in a commercially viable mining of opal in the Vernon area. As observed at the Tucson Gem Show most of these specimens were poor quality and highly cracked.
Return to Top Ca2Al2Si3O10(OH)2+Fe: Fine material suitable for cabochons are found in the Le Roi Mine near Rossland.
Return to Top : Quartz is one of the most common minerals in B.C., it occurs in many types of rock formations. Amethyst lined geodes occur at Little River Camp near Squilax, on Green Mt. Rd. near Penticton, and near Cherry Cr. Fine deposits of agate are found throughout the province. There is a great variety, ranging from fine blue agate, moss agate, banded agate, eye agate, and red agate resembling Mexican agate (locations are to numerous to mention). Along with agates other forms of chalcedony are found , including onyx, jasper, and petrified wood.
Return to Top MnSiO3+Ca: Most rhodonite deposits in B.C. are in the form of lenses occurring with bedded chert or jasper. Very beautiful rose-pink material occurs on Saltspring Island and Vancouver Island , notably on Hill 60 and Cottonwood Cr. Other rhodonite bearing sedimentary rock formations are the Shoemaker formation near Keremeos; the Cache group from Tsitsutl Mt. (near Fort St. James) extending to Williams Lake; the Fennell formation (Clearwater to Barriere); the Cassiar area; Kaslo to Slocan area; and fine pink material with black patterns from Bella Coola area.
Return to Top Na4Al3(SiO4)3Cl: Massive blue cutting grade sodalite from the Ice River area near the Kicking Horse Pass provides material for carvings, cabochons and decorative objects.
Return to Top : Although tourmaline crystals are abundant worldwide, only a few occurrences are reported in B.C. Pegmatites at the headwaters of Skookumchuck Cr. and St. Mary Lake north of Cranbrook, the Slocan Valley north of Castlegar, and Midge Cr. west of Kootenay Lake have reported some tourmaline crystals.
Pegmatite dykes on Mica Mt. south of Tete Jaune Cache and Mount Begbie south of Revelstoke contain black, green and red tourmaline.
British Columbia is not noted for its gem production (except nephrite), at the present time. Exploration and discoveries are mostly by amateur rockhounds.
Because of the great diversity of rock formations, B.C. has an immense potential for gemstone discoveries.
Arem, Joe E., Color Encyclopedia of Gemstones.
Beryllium Occurrences in Canada (report), Department of Energy, Mines and Resources.
Gemmology Canada ( Vancouver, Canadian Institute of Gemmology ).
Leaming, S., Rock and Mineral Collecting in British Columbia, Department of Mines and Resources.
MacFall, Russell P., Gem Hunter's Guide, Department of Mines and Resources.
Resources, Source Files., B.C. Ministry of Energy, Mines and Petroleum Resources.
Sinkankas, John, Gemstones of North America, 2 volumes.
This Special Issue of Gemmology Canada is published for students of the Canadian Institute of Gemmology and others interested in gemmology. The copy-right for any articles remains with the author. For further information write to the C.I.G., P.O. Box 57010, Vancouver, B.C. V5K 5G6 or phone/fax (604) 530-8569 or e-mail email@example.com
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