Bournonite (classic material) (ex Kay Robertson Collection)

Item Description

Bournonite specimens from this ancient iron mine, abandoned in 1965, are German classics. Semi-"cogwheel"-shaped, dark metallic-gray, Bournonite crystals are sitting on the underlying matrix associated with compressed rhombohedra of golden-brown Siderite. The crystals measure up to 1.6 cm, with some well-formed smooth faces. Some crystals are not complete, but overall it's a good miniature sized specimen of this desirable and seldom seend material dating back over 50 years at least! Ex Kay Robertson Collection (#3804). 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).