Copper (rare locality specimen) (ex Kay Robertson Collection)

Item Description

Please note that this specimen is possibly a slag product, and not formed by nature. I've seen a few other Coppers from Mansfeld that were slag products, and this piece is fairly similar in appearance. With that said the piece has a semi botryoidal form with an almost sparkling iridescence in areas, and a strange oxidation on the surface. Ex Kay Robertson Collection (#3266). 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).