Mineral Species: Conichalcite

Chemical Formula: CaCuAsO4(OH)

Chemical Name: Calcium Copper Arsenate Hydroxide

Mineral Class: Arsenate

Mineral Notes: Conichalcite has a unique grass-green colour which makes it hard to mistake for any other mineral. It forms in the oxidation zone of copper ores by the action of oxygen and water. Conichalcite forms a solid solution series with the Calciovolborthite. Conichalcite is the arsenic rich end member of the series and Calciovolborthite is the vanadium rich end member.

Description: Bright green, spherical conichalcite nodules up to 3 mm diameter covering matrix on both sides. Magnification of the clusters shows the stellate arrangement of the crystals within. These are very attractive.

Location: Ojuela Mine, Mapimí, Durango, Mexico.