Siderite var. Pistomesite w/ Pyrite (RARE - Robertson Coll.)

Item Description

Pistomesite is an obsolete name for a Mg-rich variety of siderite. It is VERY RARE from this highly unusual and obscure Swiss locality. Tiny pyrites are aesthetically embedded in the two pristine faces of the lustrous, translucent, tannish-olive thumbnail cleavage rhomb. The rest of the faces are cleavages. Ex Kay Robertson Collection # 10562 and acquired in 1984. 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). Rare, perhaps UNIQUE siderite with pyrite from this most unusual locale.