Malachite with Brochantite (ex Kay Robertson Collection)

Item Description

An old time specimen featuring sparkling of forest green colored Malachite and Brochantite on matrix from the famous Bisbee district in southern Arizona. There is a note accompanying the piece from Kay to an unknown recipient where she asks for help identifying the crystals. She is suspicious that it doesn't quite look like Malachite, to which the recipient responded that it "appears to be Malachite - each crystal is made up of smaller prismatic malachite xls - the external form appers to be rhombic - this would lead one to believe it were a pseudo after a rhombic mineral possibly Calcite". A cool piece for anybody who collects secondary ore minerals or specimens from Bisbee. Ex Kay Robertson Collection (#1220). 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).