Magnesite (var: Breunnerite) (ex Kay Robertson Collection)

Item Description

An unusual and rare specimen of the iron-bearing variety of Magnesite (formerly called Breunnerite) from Freiberg according to the labels. I'm not 100% certain that the locality is accurate as I can't find another piece of this material for reference, but Kay had a lot of unique specimens from isolated finds, so I'm not ruling it out. Hundreds of compressed, golden-brown rhombohedra of Magnesite have formed attractive "rosettes" sitting on a layer of black Sphalerite on gneiss matrix. The piece is crystallized on both sides and is in very good shape overall. A great piect to add to a German suite or a collection of carbonates. Ex Kay Robertson Collection (#12879). 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).