Siderite (ex Kay Robertson Collection)

Item Description

This is a classic specimen of the elusive Siderites from the Farmsen Clay Pit in Hildesheim. I can only remember seeing a few of these in person over the year. Highly compressed, beautiful chocolate brown colored rhombohedra of Siderite sit atop Septarian nodule or clay ironstone matrix. The largest crystal measures 1.1 cm across. The Siderites have a slight iridescence that gives them a semi-metallic appearance. Really attractive and VERY hard to find on the market. One reference I found online stated that these specimens were collected in 1958. Ex Kay Robertson Collection (#4556). 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). A fantastic German classic from the obscure locality. Valued at $800-$950.