Libethenite

Libethenite which is a basic copper phosphate, crystallizes in the orthorhombic system as short-to-slightly-elongated prisms, usually on cavity walls as drusy coatings with many small, protruding, wedge-shaped terminations. It is translucent to subtransparent, with colors ranging from light-to-dark green and olive-green to blackish-green. Libethenite, a copper phosphate hydroxide, usually forms short and/or slight elongated and vertically grooved or striated prismatic crystals. Libethenite is a secondary mineral forming in oxidized areas of copper deposits and is usually associated with Azurite, Malachite, and other copper minerals.