Pharmacosiderite pseudomorph after Cobaltite (ex Kay Robertson Collection)

Item Description

Please note: This specimen is labeled as coming from Cobalt, but mindat.org does not report Pharmacosiderite as occurring at this locality. It's most likely from the Brazil Lake occurrence in Ontario. With that said, it's an incredibly rare pseudomorph featuring tan colored Pharmacosiderite which has pseudomorphed after pseudo-cubic (orthorhombic) Cobaltite crystals which measure up to 8 mm. I have to say that these are the only pseudomorphs after Cobaltite that I've seen from any world locality. A must have for any fan of pseudomorphs, thumbnails, rarities or Canadian minerals. Ex Kay Robertson Collection (#10991). 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).