Arsenopyrite with Sphalerite (ex Kay Robertson Collection)

Item Description

A classic sulfide combination specimen featuring stout, sharp, well-formed, silvery-grey colored blocky crystals of Arsenopyrite measuring up to 1.5 cm sitting atop jet-black Sphalerite matrix. Minor associated Calcite can be seen on the piece as well. The Arsenopyrite crystals are in good condition, with only minor imperfections. The base of the Sphalerite matrix is understandably contacted where it was removed from the pocket wall. A worthwhile and attractive example of this historic material from Freiberg. Ex Kay Robertson Collection (#11848). Kay was a prominent California collector, who specialized in European classics. She nearly lived 100 years from April 1920 - March 2020. See the article in the March-April, 2007 Mineralogical Record ( https://www.mineralogicalrecord.com/pdfs/Kay%20Robertson%20Collection.pdf ), and the 50+ page article in the German Magazine "Mineralien Welt" November-December 2017.