Tennantite xl (RARE old Colorado) Robertson Coll.

Item Description

A fantastic and rare, super sharp, truncated tennantite crystal tetrahedron from this obscure old, extinct Idaho Springs area mine. The dark metallic gray crystal has splendent lustre. A very rare complete all-around floater thumbnail with only trivial edge and corner wear. The long extinct Au-Ag polymetallic Freeland Mine was discovered in 1861 and was worked into the early 1900s. Ex Kay Robertson Collection # 11719 and acquired from dealer Keith Williams, when he lived in Idaho Springs in the 1980s. 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). Rare, perhaps UNIQUE material from the mine, as there are no photos in the MINDAT Photo Gallery of any of the numerous species listed for the mine. A MUST for the species or Colorado collector! The crystal form is superlative.