Iridescent Siderite (ex Kay Robertson Collection)

Item Description

A great piece for any fan of Bisbee material or Arizona minerals. This cabinet sized display specimen is filled with hundreds of chocolate brown Siderite crystals with a rarely seen iridescent coating (presumably of some copper species) to create a very colorful and showy overall specimen. The display side is in excellent condition, with no major damage that I can see with the naked eye. These were quite rare in my experience, as I've only had a handful of them to offer over the years. Ex Kay Robertson Collection (#1078) with an old label from The Bradley mineral dealership in Los Angeles. 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).