Pharmacosiderite with Jarosite and Scorodite (ex Kay Robertson Collection)

Item Description

A beautiful specimen of these old classic and how very hard to find Pharmacosiderites from the Richmond-Sitting Bull Mine, near Lead, South Dakota. This piece is loaded with dozens upon dozens of very sharp, lustrous, rich olive green colored cubic crystals of Pharmacosiderite measuring to about 1 mm associated with minor yellowish colored Scorodite. The label also mentions that the piece is associated with Jarosite, but the species is not reported from this locality on mindat.org. If you have a good microscope or a strong loupe, you can have a lot of fun looking at all the gorgeous little crystals on this specimens. We photographed the piece with a Canon MP-E 65 mm macro lens to better illustrate the quality. Ex Kay Robertson Collection (#7321). 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.