Mineral Species: Olivenite, Cu2AsO4(OH), Copper Arsenate Hydroxide.

Mineral Notes: Olivenite is a rare secondary copper mineral characterised by its dark olive green color, hence the name. It is found in extensively weathered, highly concentrated copper sulfide ores. The mineral has the same internal structure as Libethenite and Adamite. This means that they share the same symmetry and crystal shapes.

Description: A diamond-shaped steel-gray matrix covered by several flake-like deposits of dark green Olivenite. One pocket shows a particulalry good group of crystals fused together into a botryoidal formation. This is best viewed under magnification. The luster is a very bright vitrous-looking giving the Olivenite a rather unusual appearance.

 Location: Wheal Phoenix Mine, Cornwall, England.