Smithsonite (Carbonate)

ZnCO3

Hardness: 4.0 - 4.5
Specific Gravity: 4.43

Characteristics: Usually brown or blue amoung other colors; perfect rhombohedral cleavage; subconchoidal fracture; pearly, vitreous luster; transparent to translucent.

Found in zinc deposits, especially, in carbonate rocks.

Smithsonite is used as a minor ore of zinc and as mineral specimen.

(Primary text: Perkins, D. 2002. Mineralogy. Prentice Hall.)