Chalcopyrite coating Sphalerite (ex Kay Robertson Collection)

Item Description

A beautiful multi-generational sulfide specimen from this historic mine in Germany. Sharp, well-formed, groups of Sphalerite formed on Chalcopyrite and Quartz matrix, but were later coated by a second generation of Chalcopyrite to create this show and very eye-catching display specimen. The largest crystal group measures 1.3 cm across. You can see on the back of the piece that there are some exposed groups where the dark brown-black Sphalerite is still visible. Very good condition overall, and gorgeous in person. The Chalcopyrites have a somewhat direction luster with a pseudo-"drusy" appearance on the surface. Ex Kay Robertson Collection (#4486) along with a label from Mitch (Mike) Gunnell that states it was acquired from the P Jonas collection in 1946. 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).