Azurite partially altering to Malachite (classic material) (ex Kay Robertson Collection)

Item Description

Classic material from Bisbee featuring sharp, lustrous, rich azure blue colored crystals of Azurite which are starting to alter to Malachite with minor oxidized matrix. Good quality up close, and certainly a worthwhile add to a secondary ore collection or a suite of Arizona minerals. I love the fact that the piece came with such a specific locality, as most of these specimens are very generalized in their pedigree. An EARLY entry from the Kay Robertson Collection (#537). Considering the collection had over 15,000 specimens, anything in the 500s was added many decades ago. 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).