Erythrite

This specimen is Erythrite from the Mount Cobalt Mine, Selwyn, Queensland, Australia, measuring 83 x 60 x 25 mm and weighing 127 g. It is drawn from the David Vince Collection. Erythrite is a hydrated cobalt arsenate, and its characteristic crimson to pink colour has long made it a marker mineral for cobalt mineralisation, earning it the old miners' name "cobalt bloom." The Mount Cobalt Mine, as its name suggests, is a locality defined by cobalt-bearing ore, and Erythrite typically forms there as a secondary mineral through the oxidation and alteration of primary cobalt-arsenic minerals near surface. Its presence is often the first visible sign, to the eye in the field, that cobalt mineralisation is close by. At 83 x 60 x 25 mm, the specimen has good cabinet presence for the species, which more often occurs as thin crusts or coatings than as a substantial piece. Erythrite is a soft, delicate mineral, so a stable, low-traffic display position is recommended. The specimen's documented provenance is the David Vince Collection.