Arsenopyrite pseudomorph after Pyrrhotite (ex Reynolds and Robertson Collections)

Item Description

A really cool and very hard to find pseudomorph of dark grey Arsenopyrite replacing pseudohexagonal crystals of Pyrrhotite, along with what according to label appears to be pseudomorphs of Marcasite after Pyrrhotite as well. For what it's worth, I found one listing online that said that the "cores" of the pseudomorphs are actually Marcasite, and the Arsenopyrite is epitaxially overgrowing them. The largest pseudomorph measures 6 mm across. The piece is nearly a complete "floater", as it is crystallized on all sides, with no major damage anywhere. Priced at $500 in the inventory. This piece comes to us from the collection of Bob Reynolds, well-known fossil and mineral expert and former Curator of Earth Sciences at the San Bernardino County Museum in California. Originally the specimen was in the collection of Kay Robertson (#9822). 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.