Cassiterite (old classic material) (ex Kay Robertson Collection)

Item Description

A classic from the historic mining area at Horni Slavkov (SchlaggenwalI featuring sharp, well-formed, rather lustrous, jet black colored crystals of Cassiterite measuring up to 5 mm on semi-metallic Zinnwaldite mica matrix. The label mentions that one of the crystals is translucent, but I can't find one that passes light. Good quality and now hard to find on the market from this old famous mining district. Ex Kay Robertson Collection (#7780) with a mention on the label that it came from Willy Hirsch of Munich. Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record and the 50+ page article in the German Magazine "Mineralien Welt" November-December 2017).