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  Copyright / Reprints Emerald in Canada
By Willow Wight
INTRODUCTION Emerald is a newcomer to the Canadian gemstone scene. John Sinkankas, in his comprehensive book Gemstones of North America, Volume III, published in 1997, mentioned many beryl localities in Canada, but none for emerald.
Before 1999, only a few isolated specimens of verified emerald were reported from widespread localities in Canada (Wilson, 1997; Wight, 1999). In the fall of 1998, emerald was serendipitously discovered by Bill Wengzynowski of Expatriate Resources while he was exploring a base metal anomaly on their Goal Net property in the Finlayson Lake district of southeastern Yukon. The surprising announcement of emerald in the Yukon was reported on their website on December 2, 1998, and thus began a new era of interest in the beautiful green beryl. More mining companies, perhaps spurred by the success of the diamond mining companies in the North, began to take an interest in coloured gemstones. See Wight, 1999. Strong attendance at the gemstone workshops at the Yukon and Whitehorse Geoscience Fora in November, 2002, also indicates an increasing interest in gemstones in Canada's North. See report on p. 67. LOCALITIES British Columbia Wilson (1997) reported that he had found emerald-green beryl in 1989 in narrow quartz-calcite-pyrite veins that cut volcaniclastic rocks adjacent to a quartz monzonite intrusive on Red Mountain (near Stewart), British Columbia. Since then several other specimens have been found in the area by geologists who were searching for gold. Microprobe analysis shows that this beryl is coloured by traces of vanadium. The small crystals have all been fractured and opaque. Ontario In Ontario, a small specimen of emerald was found at the Taylor #1 pegmatite, Mavis Lake rare-element pegmatite group near Dryden, Brownridge Tp., Kenora district (Breaks and Moore, 1992). A medium-light green, irregularly shaped, faceted emerald weighing 0.13 carat is now in the National Gem Collection at the Canadian Museum of Nature, Ottawa (CMNGE 21578). The rough was donated by Fred Breaks, and faceted by Brad Wilson in 1995. Electron microprobe analysis confirmed the presence of chromium. Northwest Territories Lened property The first discovery of emerald in the Canadian North was made in 1997, by prospector Ronald Berdahl, who found emeralds near the Lened tungsten showing in the westernmost Northwest Territories, very close to the Yukon border. The Lened property, then owned by Liberty Mineral Exploration Inc., is underlain by a rare-element-enriched, two-mica pluton and associated pegmatites. The emeralds are coloured by vanadium, and are up to 2 cm long and 0.5 cm wide (Yukon Geology website, 2001). In July, 2002, a short field study was carried out to identify the setting for the emeralds at the Lened property, a tungsten skarn deposit, 50 km north of the Cantung mine in the Selwyn Mountains (Falck, 2003). Nearby intrusions were examined as potential sources of beryl. The emeralds occur in a small, metasomatized limestone lens east of the main tungsten showing. The 100 x 20-metre skarn lens is cut by at least 35 significant quartz veins, of which approximately 80% contain green beryl. The beryl crystals found were too pale and small to be considered of economic importance, but there was a high proportion of transparent crystals. The setting of the skarn, in fault contact with black shales and in proximity to a granitoid intrusion, is not uncommon in this part of the Cordillera. Prospectors can keep this setting in mind as they search. The discovery of more and better quality emeralds would not be unexpected. Yukon Territory The Crown Showing at Regal Ridge Emerald in the Yukon was first discovered by Expatriate Resources' field geologist, Bill Wengzynowski in 1998, while he was exploring their Finlayson Lake property for base metal deposits. The discovery has been fully documented on their website. Because the "Crown showing" indicated a promising zone of emerald mineralization, Expatriate launched Regal Ridge as a separate project. The property is located high in the southeastern Yukon's rugged Pelly Mountains, 230 km northeast of Whitehorse, 42 km south of the Robert Campbell Highway (61°16.6'N, 130°35.5'W, NTS 105G/7). Access is difficult and requires expensive helicopter transportation. EXPLORATION AND DEVELOPMENT AT REGAL RIDGE Expatriate began to evaluate the Regal Ridge emerald showing in 1999, including small-scale test mining and systematic exploration of the surrounding area. Numerous green beryl and emerald-bearing float trains were discovered in a 900 by 400-metre area on both sides of the ridge. Washing and handsorting of ~6 m3 of material from float trains and trenches yielded >6 kg of green beryl and emerald crystals. In mid-2001, True North Gems Inc. entered into an option agreement with Expatriate to acquire a 50% interest in the property. True North's summer season of 2002 encompassed installation of camp facilities, road construction and pilot mill installation, mechanical trenching, and geological and geochemical surveys. Emerald-bearing material was crushed, washed and passed over a moving belt for handpicking. Geological mapping and surveying provided useful information, and three additional emerald showings were found. A small drilling program was carried out to determine the continuity of mineralization at depth. Eight bulk samples totaling 114 tonnes were taken from trenches in four different zones. These were processed on site to produce 53 kg of emerald concentrate, which was transported in sealed containers to Vancouver for sorting, cutting and evaluation.
On November 27, 2002, True North completed its purchase of 100% interest in the Regal Ridge property from Expatriate Resources. The purchase was made possible by the success of the Initial Public Offering of True North Gems, and the listing of their stock as a public company on the TSX Venture Exchange. In December, 2002, bulk sample results were announced confirming the high concentration of gem-grade emerald. The southwest zone was the most promising with yields of 19.09 g/tonne gem quality and 92.35 g/tonne near-gem quality. Gem quality is defined as transparent and suitable for faceting; near-gem material is translucent and suitable for cabochons. Also in December, 2002, True North acquired the services of Archer Cathro Associates (1981) to undertake a regional exploration program in 2003. The deal included access to their proprietary geological database, which contains 40 years of geological data and covers areas of the Yukon rich with potential for gemstone occurrences. One of the Archer, Cathro partners is William Wengzynowski, the original discoverer of emerald at Regal Ridge. In addition, Dr. Lee Groat of the University of British Columbia will take part in the field program. On February 4, 2003, True North Gems approved a $2.1 million exploration program for the 2003 field season. Surface and underground work will evaluate and explore the emerald-bearing mineralization with the highest potential as determined in 2002. Potential targets for underground work are the emerald-rich Southwest and the promising West, BG and #4 zones. Drilling in June will determine the sites for installation of up to three portals. Plans include improving the existing facilities to accommodate 30 people and building a 750-metre airstrip adjacent to the camp. Access to the Regal Ridge site has been difficult and expensive, requiring the use of helicopters-thus the need for the airstrip suitable for fixed-wing aircraft. To get some mechanized equipment into the site, in 2001 an excavator was "walked in" over an environmentally sensitive valley. Permits first had to be obtained from the Yukon government, which maintains high environmental standards, but is also sympathetic to mining. In April, 2002, True North was able to move in heavy equipment over ice roads, in order to carry out their bulk-sampling project. True North hopes to become a wholesaler of cut emeralds, targeting the Canadian jewellery market in general and the local tourist industry in particular. Their business model of marketing emeralds as a Canadian product, using Canadian diamonds as a template, doesn't really compete with established emerald channels. True North now has to determine whether there is enough emerald to support planning for a mine. One estimate is that emerald gems could be sold in Canada by the fall of 2004. EMERALD FROM REGAL RIDGE A first scientific study (Groat, et al., 2001) discussed the geology and mineralogy of the Crown showing, and inclusions that were observed in the emerald. A recent and very comprehensive paper published in the Canadian Mineralogist on the emerald from Regal Ridge, Yukon, says it all. The fifteen authors described the geology and mineralogy of the showing and investigated its origin. (Groat et al., 2002).
To summarize: The emerald crystals occur where quartz veins cut mica-rich layers in a shallowly dipping mica schist. Quartz veins associated with emerald range in width from 0.5-1 m. At least eight such veins have been found on the north side of the ridge. Most are surrounded by a much more extensive mass of fine, dark tourmaline crystals. Green beryl crystals up to 4 cm in length occur in tourmaline zones and, rarely, in the quartz veins. Some smaller emerald crystals and sections of larger ones are of gem quality. Chromium is the predominant chromphore (average Cr content of 3208 ppm.). The close proximity of a contemporaneous granite suggests that it is the source of beryllium. The source of chromium is the schist. Electron microprobe analyses of the chemical composition of the emeralds showed vanadium contents ranging from 0.0 to 0.05 wt.% V2O3, and chromium contents ranging from 0.36 to 1.14 wt.% Cr2O3. Refractive indices are in the normal range for emerald: ne = 1.571 to 1.578 and no = 1.578 to 1.584. Measured densities ranged from 2.678 to 2.719 g/cm3. CONTINUING EXPLORATION After the sale to True North Gems of its interest in the Regal Ridge Emerald property, Expatriate Resources has continued its search for emerald on its more than 750 km2 of mineral claims in the Finlayson District. The favourable conditions for the formation of emerald appear widespread in the Finlayson District. On November 14, 2002, Expatriate announced an agreement with YK Group whereby YK Group may acquire a 60% interest in the exploration and development of the gemstone potential of Expatriate's Finlayson District claims, which consist of 2900 claims, many adjacent to Regal Ridge. Expatriate has a large database for the Finlayson District from its exploration for massive sulphide deposits. This proprietary information will be used to guide exploration where the potential for multiple emerald occurrences appears high. True North has expanded its operations by completing an option agreement with Firestone Ventures Inc. (Dec 2002), whereby Firestone will fund exploration in 118 mineral claims staked by True North Gems in the Finlayson District. In January, 2003, True North received approval to acquire 337 claims in the Finlayson District staked by Glacier Gems. On February 11, 2003, True North announced the acquisition of five new, highly prospective claim groups in the Finlayson District, and has approved an additional $470,000 exploration budget for 2003. Access to the Archer Cathro & Associates database, acquired in December 2002, led to these promising claims (220 mineral claims, covering an area of 46 km2). Recent staking by others in the region indicates that other companies will be actively exploring for emerald during 2003. CONCLUSIONS The discovery of emeralds at two locations along with many reports of beryllium in the northern Cordillera suggests the potential for more emerald to be discovered in the Yukon, western Northwest Territories and northern British Columbia. Groat and Marshall (2002) stated, however, that neither Lened nor Regal Ridge appear to fit existing genetic models for emerald deposits, suggesting that existing exploration guidelines will be of limited use, and that new guidelines will need to be formulated. The type of setting at the Lened occurrence (a skarn, in fault contact with black shales and in proximity to a granitoid intrusion), while atypical for emerald, is not uncommon in this part of the Cordillera. Now that the quite ordinary setting has been described, prospectors can keep this model in mind as they search. The discovery of more and better quality emeralds would not be unexpected. The skarns at both Lened and Regal Ridge are scheelite bearing. At Regal Ridge the scheelite is often intimately associated with emerald. Nighttime or dusk prospecting is possible with an ultraviolet lamp. (T.S. Ercit, Pers. Comm., 2003) Over many years of prospecting and exploration, both Expatriate Resources and Archer Cathro have developed proprietary databases of rock types and deposits. This information is being used to target certain areas with potential for gemstone occurrences. This technique is commonly used by mining companies that are searching for base metals. It is significant that these databases are now being used to point the way to gemstone deposits such as emeralds in the Finlayson Lake area. REFERENCES Breaks, F.W. and Moore, J.M., Jr., (1992) The Ghost Lake batholith, Superior Province of Northwestern Ontario, Canadian Mineralogist, 30, p. 835-875. Canadian Gemmologist (2002) 23(3); Cover of the Autumn issue shows a 2.10-ct emerald cabochon from Regal Ridge. Expatriate Resources Ltd., <http://www.expatriateresources.com> Falck, H. (2003) Lened emerald study, C.S. Lord Northern Geoscience Centre, Yellowknife. <www.nwtgeoscience.ca/NewFiles/emeralds_project.html> Groat, L.A., Ercit. T.S., Marshall, D.D., Gault, R.A., Wise, M.A. Wengzynowski, W. and Eaton, W.D. (2001) Canadian emeralds: the Crown showing, southeastern Yukon, Canadian Gemmologist, 22(3), p. 92-95. Groat, L.A., Marshall, D.D., Giuliani, G., Murphy, D.C., Piercey, S.J., Jambor, J.L., Mortensen, J.K., Ercit. T.S., Gault, R.A., Mattey, D.P., Schwarz, D., Maluski, H., Wise, M.A., Wengzynowski, W. and Eaton, W.D. (2002) Mineralogical and geochemical study of the Regal Ridge emerald showing, southeastern Yukon, Canadian Mineralogist, 40, p. 1313-1338. Groat, L.A. and Marshall, D.D. (2002) Emeralds in Canada: recent discoveries and exploration guidelines, CIM Conference, Vancouver. <www.cimvancouver2002.org/Abstract.cfm?PaperNum=513&SID=28> Mêlée & Macles (1999) Canadian Gemmologist, 20(1), p. 25. Mêlée & Macles (2001) Canadian Gemmologist, 22(3), p. 99. Neufeld, H.L.D., Groat, L.A. and Mortensen, J. (2003) Preliminary investigations of emerald mineralization in the Regal Ridge area, Finlayson Lake district, southeastern Yukon. In: Yukon Exploration and Geology 2002, D.S. Emond and L.L. Lewis (eds.), Exploration and Geological Services Division, Yukon Region, Indian and Northern Affairs Canada, p. 281-284. <www.geology.gov.yk.ca/publications/yeg/yeg02/index.html> True North Gems Inc., <www.truenorthgems.com> Wight, W. (1999) Explosion of new interest in Canadian gemstones, Canadian Gemmologist, 20(2), p. 45-53. Wilson, B.W. (1997) Gemstone occurrences in British Columbia, Canadian Gemmologist, 18(3), p. 74-86 Yukon Geology Program, <www.geology.gov.yk.ca/special/index.html>
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Reprint Acknowledgements: This article was originally published in the Summer 2003 (Vol. 24, No. 2, p. 61-66) issue of the Canadian Gemmologist, the official journal of the Canadian Gemmological Association. The Canadian Rockhound is pleased to reprint this article with kind permission of the author and the editor of the Canadian Gemmologist. For more information about the Canadian Gemmologist, please visit: www.canadiangemmological.com. The Canadian Rockhound also thanks True North Gems for granting the magazine permission to use the emerald photographs appearing in the article. These photographs were not published in the original article. Reprint instructions:This article may not be copied, distributed or reprinted in any form without permission from the author. To contact the author, please use the e-mail address provided. If you are unable to contact the author, please contact the Canadian Rockhound. Authorized reprints must acknowledge the author, original source, and the Canadian Rockhound. The emerald photographs appearing in the article were obtained from True North Gems. The photographs may not be copied, distributed or reprinted in any form without permission from True North Gems. To contact True North Gems, please visit: www.truenorthgems.com. 
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WIGHT, Willow. Emerald in Canada. Canadian Rockhound [online]. 2003, vol. 7, no. 2. Available from World Wide Web: <http://www.canadianrockhound.ca/2003/02/ WIGHT, W. (2003) Emerald in Canada, Canadian Gemmologist, 24(2), p. 61-66.
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