Pyrite altering to Tennantite (RARE!) Robertson Coll.

Item Description

Well-crystallized pyrite is very rare and pyrite in general, is rare from renowned Tsumeb, due to the lack of iron in the deposit. This is a SUPER RARE and sculptural small cabinet specimen of lustrous, sharp, pyritohedrons altering to tennantite! Every turn and face highlights this rare and fascinating alteration. Ex Kay Robertson Collection # 2876 and acquired in 1963. 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). A very rare, perhaps UNIQUE specimen of sharp pyrite crystals altering to tennantite from Tsumeb! Value?? A MUST for the Tsumeb, pseudomorph or species collector.