June 22nd, 2010 10:06
Turquoise: True, blue or both?
If you really want the scoop on your favorite gemstone, start by asking a miner! Dayton Simmons, a miner and dealer from Santa Fe, who has been in the business since he was 12, set the record straight recently when he talked about turquoise to the San Francisco Metal Arts Guild (23 May, 2010).
It was news to me that only 5% of all mined turquoise is gem quality, meaning it is relatively hard, with a Moh rating of 5.5-6.5. As for everything else, well it’s softer and more fragile, often to the point of being chalky.
Native craftspeople have always had their own favorite ways of improving the color and relative porosity of this lovely stone – remedies including soaking in water or rubbing on body oils. Commercial stabilization – impregnation with plastic – began in 1950, followed by reconstitution, enhancement, and a brand new (secret) process called Eljen that substantially hardens the material.
There’s still turquoise mining in the southwest, but you’d better check the credentials of any dealer you patronise. ‘Tibetan’ turquoise? Forget it – most of the lower cost turquoise comes from China, of course. ‘White Buffalo’? A nice material, but it shouldn’t be called turquoise.
How about the pieces you inherited from your family? If they’re older than 1950, the stones are almost certainly gem quality. Modern look-alikes? The pieces Simmons showed us looked old but weren’t. He’d had local craftspeople create new ‘old style’ pieces with gem quality stones. Full marks for disclosure!
If a piece in your collection needs repair, talk to Simmons. (Silver Day Trading Co., PO Box 22716, Santa Fe, NM. 87502, 505 982-3310.)
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