This content was first published on IGR – Italian Gemological Review no. 10 in 2020. The information provided here is therefore current as of the original publication date.
A discovery that has greatly interested gem lovers and the entire gemological community is reported by the London-based “Journal of Gemmology” in its issue no. 37, 2020. Diaspore, an Aluminium hydroxide featured by the Italian Gemological Review (IGR) in its no. 0, released in January 2017, is known for its trichroism (with colors ranging from kiwi green to magenta to red) and is traditionally found in deposits in Turkey, precisely in the province of Mugla, marketed under the name of Zultanite. But no one would have expected surprising light pink diaspores to be found in new deposits in Afghanistan’s Goshta district. These crystals show a different pleochroism than the examples of the Turkish deposits. If viewed under warm light the stones shows a very light pink, while if viewed under cold light a dazzling purple becomes evident.
Mark H. Smith, co-author of the article and active in the trade too, revealed last May that he obtained a 70 g rough gem from an Afghan supplier with a yield after cut of 35 stones ranging from 0.50 to 10.91 ct.
Diaspore is known to be difficult to find in gem quality and is very complicated to cut, so much so that only skill cutters are in charge of faceting it as they need to know where the best cutting directions can be found, considering the cleavage and allowing for the best possible pleochroism. A 46.97 cts gem specimen, the largest of those obtained from this new Afghan variety, is currently in the Herb and Monika Obodda collection.
Gem News published on IGR – Italian Gemological Review #10, Autumn 2020
