Boulangerite (rare) (ex Kay Robertson Collection)

Item Description

This specimen came labeled as coming from a locality called the "Goldberg Mine near Muesen". I can't find a listing for any Germany locality called the Goldberg Mine, so I'm leaving it as is. If anybody out there is faimiliar with this material, and its proper locality designation, please let us know. With that said, this is a dense, solild compacted mass of silvery-grey Boulangerite free of matrix. The piece weighs a whopping 392 grams. An odd and rare example of this hard to find lead antimony sulfosalt. Ex Kay Robertson Collection (#2468). 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).