Cassiterite
Herbb II Pegmatite
Powhattan Co, Virginia

This specimen measures 8.5cm x 7cm






Cassiterite      SnO2

Simple Oxide; tin oxide, often with some iron

Color and Luster: Brown, black; rarely yellow, gray; greasy or adamantine to dull; streak white to light brown

Hardness: 6-7

Cleavage: Distinct

Fracture: Uneven, brittle

Crystals: Tetragonal, generally in short prismatic twinned crystals; also can be granular, desseminated, reniform with radiating fibrous structure(wood-tin)




Note: Largest known single crystal to come from North America

Photo by Mary Sutherland


Descriptions taken from
The Audubon Society Field Guide to North American Rocks and Minerals