Rocks and Minerals

Pyrite

Composition FeS 2 - Iron disulfide
Color Pale yellow to brassy gold
Luster Metallic, sometimes iridescent
Streak Greenish black
Hardness 6 - 6.5
Cleavage None
Other Properties Produces sparks if struck against steel

Galena

Composition PbS - Lead sulfide
Color Lead-gray
Luster Very bright metallic
Streak Lead-gray
Hardness 2.5 -2.8
Cleavage Cubic
Other Properties High specific gravity (very heavy)