Siderite var. Spharosiderite (RARE - old) Robertson Coll.

Item Description

Spharosiderite is the rare microcrystalline, botryoidal variety of siderite. It is EXTREMELY RARE from the historic and famous mines at Ste Marie. An impressive large 2.8 cm botryoid with a nubby surface, sections of other botryoids and striking sharp unusual elongated rounded siderite crystals fill a sculptural vug in dense basalt matrix. Ex Kay Robertson Collection # 8074 and acquired from the Cisneros' in February, 1977. It was previously in a German collection. 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 French siderite from this renowned locale.