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

Item Description

Classic and very showy old-time two-sided combination material from this famous and historic locale. Intergrown clusters of lustrous, translucent brown to yellow spharosiderite, a rare botryoidal variety of siderite dramatically cover the terminations of a dense intergrown cluster of glassy barite blades. The striking 2.8 cm long cluster of botryoids across the top looks like a segmented caterpillar or worm! Ex Kay Robertson Collection # 8355 and acquired from the Cisneros' in 1977. 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).