Template:POTD/2011-01-20
A sample of malachite, a green copper carbonate mineral that crystallizes in the monoclinic crystal system. It is typically associated with copper deposits around limestone, and is often found together with azurite. Malachite was used as a mineral pigment in green paints from antiquity until about 1800, and is still used today for decorative purposes and to make jewelry.Photo: JJ Harrison