Otavite, Tsumeb, Oshikoto Region, Namibia
Otavite is a rare cadmium carbonate mineral with the formula CdCO3. Otavite crystallizes in the trigonal system and forms encrustations and small scalenohedral crystals that have a pearly to adamantine luster. The color is white to reddish to yellow brown. Its Mohs hardness is 3.5 to 4 and the specific gravity is 5.04. Associated minerals include azurite, calcite, malachite, and smithsonite.