Pharmacosiderite (old classic) British Museum

Item Description

Pharmacosiderite, a hydrated K-Fe arsenate, is a classic and desirable accessory species from the famous and historic mines of Cornwall. Sparkly, gemmy, green microcrystals fill a sculptural vug in quartz matrix. The green crystals cover terminated quartz points, some with an iron oxide coating, adding color variability. OLD-TIME material, as primary production was over by 1852 at Wheal Gorland! This historic mine produced ore intermittently from 1792-1909. The piece has a fine provenance, as it was formerly in the British Museum and comes with the label. Ex Kay Robertson Collection # 1890 and acquired from Scott Williams in February, 1961. 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). Classic, old English material, seldom seen now in any size or quality.