Pyrite ps. After Marcasite on oil shale (RARE) ex Kay Robertson Coll.

Item Description

Mineral specimens of any type are rare from this obscure Nebraska quarry and matrix specimens are EXTREMELY RARE! A 1.2 cm, lustrous, brassy, pyrite pseudomorph after a sharp marcasite octahedron with striking hoppered faces is jauntily perched atop the oil shale matrix. A rare, perhaps unique matrix pseudo from this locale from the Kay Robertson Collection # 12622. Kay is a prominent California collector, who specialized in European classics (see the article in the March-April, 2007 Mineralogical Record).