Malachite pseudomorph after Azurite (ex Kay Robertson Collection)

Item Description

The famous copper producing locality at Concepción del Oro is famous for some impressive sulfides, excellent Scorodites and even some fine pseudomorphs of Malachite after Azurite. This toenail size specimen features several thick, "sword"-shaped crystals of velvety forest green Malachite that have completely replaced the original Azurites sitting on prismatic, grey Quartz matrix. The largest pseudomorph measures 2.6 cm long. No major damage, but there is a bit of roughness along one edge of the pseudomorphs. Overall it's a very showy and choice example of this seldom seen material. Ex Kay Robertson Collection (#5145). Kay was a prominent California collector, who specialized in European classics. She nearly lived 100 years from April 1920 - March 2020. See the article in the March-April, 2007 Mineralogical Record ( https://www.mineralogicalrecord.com/pdfs/Kay%20Robertson%20Collection.pdf ), and the 50+ page article in the German Magazine "Mineralien Welt" November-December 2017.