Galena
Golden Mine
Joplin, Missouri
This specimen measures 17 x 11 cm with individual cubes up to 3 cm
Galena PbS
Lead Sulfide
Color and Luster: Dark lead-gray; metallic
Hardness:2.5
Cleavage: Perfect in three directions, all at 90°
Fracture: Subconchoidal(rare)
Crystals: Isometric; commonly in cubes and combinations of cubes and octahedrons; dodecahedrons less frequent; also massive an din cleavage fragments, coarse or fine grained, fibrous
Photo by Mary Sutherland
Descriptions taken from
The Audubon Society Field Guide to North American Rocks and Minerals