Azurite altering to Malachite (ex Kay Robertson Collection)

Item Description

Originally, this piece was labelled as coming from the Middle Atlas Mountains in Morocco, but it's almost certainly from Touissit. Sharp, well-formed, lustrous, prismatic, deep midnight blue colored crystals of Azurite measuring up to 2.0 cm are partially altering to forest green, velvety Malachite free of matrix. The display side is virtually damage free, while it is contacted on the back where it was removed from the pocket. Classic material from Touissit and some of the smaller Azurites actually show a bit of translucency near the edges when strongly backlit. Ex Kay Robertson Collection (#9212). 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 Velt" November-December 2017).