Malachite pseudomorph after Azurite (classic material) (ex Kay Robertson Collection)

Item Description

Long before classic localities like Tsumeb or anything in North America, these specimens were among the first known pseudomorphs of Malachite after Azurite. It's quite possible that Azurite may not have been known as a species when these specimens were first found, so these were simply Malachite specimens. The historic copper producing region around Rudabanya dates back to medieval times, and has produced some fantastic mineral specimens. This toenail is a fantastic display specimen of this old classic material featuring sharp, notably lustrous, velvety, rich green colored crystals of Malachite which have replaced the preexisting Azurite aesthetically sitting on matrix. Minor Calcite crystals can be seen on the piece as well. A great specimen of this now very hard to find material. Ex Kay Robertson Collection (#7994) mounted in an old Willard "Perky" Perkin box. 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).