Malachite (Copper Carbonate Cu2 (CO3) (OH) 2) is a beautiful green color. It has various shades. Important deposits are in the Urals, the Democratic Republic of the Congo, Chile, Namibia and Australia. The sample presented here is the cut of a stalagmite from the Katanga copper belt, south of the Democratic Republic of Congo and northern Zambia. (Thanks, Google Translate.) Image credit: Bruno Cupillard.