Galena is a metallic mineral belonging to the mineral group known as the sulphides. Its chemical composition is PbS. It is an economic mineral mined for lead, a metal used in making ammunition (its biggest use), batteries, brass and bronze alloys, and as an additive in pesticides. Lead is also used to protect human from X-ray and gamma radiation. Galena has a light silver gray colour, with a distinctive metallic lustre, and is characteristically very heavy because of the lead component (S.G is ~ 7.58). Its streak is dark gray. Based on the Moh's hardness scale, the hardness of galena is 2.5. It has a perfect cleavage in three directions at 90o angle and a cubic crystal system. The mineral is non-magnetic.
References
Cairncross, Bruce. Field guide to rocks & minerals of Southern Africa. Struik Publishers. Malaysia. 2004.
Dreyer, Lacey. Galena-Mineral Economic Value and Use Reports. Availabe: http://www.emporia.edu/earthsci/amber/go336/reports.htm#galena. Last viewed 12/06/2010.
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