Olivenite

Unknown Owner

The look and feel of this Cornish Olivenite specimen give the impression of significant age, perhaps far older than even the old handwritten Francis Henry Butler (1849-1935) label which accompanies it. The type of crystallization seen with this Olivenite is quite distinctive too, forming delicate sprays of silky acicular crystals within cavities in intensely oxidized Chalcopyrite-bearing ore. This rusty gossan also contains a tiny patch of Chalcophyllite on the back. Recorded by Butler as from "St. Day United mines" that, during his lifetime, encompassed a very broad tract of land including Poldice mine (which itself included Wheal Gorland) and Carharrack. If I was a betting man - and I am not - I would say that it looks most like older specimens from the Carharrack mine. Ex Martin Kershaw Collection, no. 584.