Green Nephrite Jade Attracts Buyers in Tucson
A tectonic belt running from Alaska through British Columbia to Mexico favours the formation of nephrite. Tectonic and lithological contacts are the predominant ore body controls. BC has more than 50 known nephrite deposits, distributed mainly along tectonic inclusions of country rocks, dykes and mafic rock layers within serpentinites, or along the contact between serpentinite and the wall rocks. This formation is very similar to other green nephrite occurrences all over the world. Nephrite is found both in situ and as boulders; the Polar Pride boulder, found in BC’s Polar mine, is a well-known example of the latter (figure 2).
Nephrite boulders are the products of erosion from the last ice age. They are usually drilled or sawn to test the quality, and only the good-quality material is transported for sale. While some of today’s nephrite is from boulders, primary deposits supply the bulk of BC’s production. This is partially due to the lack of high-quality boulders; however, the growing demand and price paid for nephrite also make it profitable to mine the primary deposits.
According to Kirk Makepeace, president of Jade West Group, the price of jewellery-grade jade from BC (figure 3) has experienced at least a tenfold increase from a decade ago. Before 2008, top-quality nephrite from BC sold for about $20 (£13) a kilo; equivalent stones now range from $200 (£130) to $2,000 (£1,300) a kilo.
The annual production of nephrite jade in BC is about 400 tons. Most of the production comes from four active mines; together, they produce about three-quarters of the world’s high-quality green nephrite. Of these four, Jade West operates the Polar, Ogden and Kutcho Jade mines. Jade West also deals with material from Wyoming and Siberia. Over the last 10 years, approximately 90% of the company’s BC production was exported to mainland China; the remaining 10% was sent to Taiwan, Vietnam and Thailand.
Jade West sends almost all of its rough nephrite to Guangdong for carving and jewellery manufacturing, with designs customised for different markets (figure 4). In addition to traditional carvings and jewellery, there is demand from South-east Asian countries for giant Buddha statues and from Western countries for home decorations. This demand leads Mr Makepeace to be very optimistic about the future availability of BC nephrite.
About the Author
Tao Hsu is the technical editor of Gems & Gemology.