Friday, 18 November 2016

Turkish diaspore - Csarite/Zultanite

Diaspore is one of the three component minerals of the aluminum ore bauxite. Though most forms of diaspore are of little interest, large crystals unlike any others were found in Turkey in the 1950's in a commercial bauxite deposit.

This deposit has become the only source of gem-grade crystals. Diaspore is one of the lesser known of the color-change gemstones. Diaspore has good hardness at 6.5-7 on the Mohs scale, but it is known to be brittle and can cleave.
In 2014 two large, rare, color-changing gemstones were donated to the Smithsonian Institution’s National Gem Collection, thanks to Milenyum Mining Ltd.

The Dubai-based miner donated the stones, a 44.48-carat faceted oval-shaped diaspore and a 159.33-carat cat’s eye cabochon diaspore, at the American Gem Trade Association’s GemFair.
The trade name Csarite was first applied to this naturally color-changing diaspore. It is now referred to as Zultanite. Milenyum is the only company that mines the gemstone.