Chemical Formula: PbS
Color: Metallic gray
Importance: Galena is mainly used as an ore for lead. Lead from galena is used in lead-acid batteries, which are used in cars, ammunition, solder, and roofing materials.
Other Interesting Information: Almost always forms and breaks into the shape of a cube. Is very dense and heavy, limiting its usefulness in pure form.
My Take: Galena is one of the easiest minerals to identify. It has so many special properties that make it truly unique.
For More Information: http://www.minerals.net/mineral/galena.aspx