Cassiterite
Mineral SnO2
Also called Tinstone and Wood tin
About it
Heavy brown to black prisms with an adamantine shine, often twinned in elbows; its weight gives it away. The chief tin ore, from Cornwall, Bolivia, and China; wood tin is a banded, fibrous form.
- Type
- Mineral
- Group
- Oxide, rutile group
- Formula
- SnO2
- Hardness (Mohs)
- 6–7
- Specific gravity
- 6.8–7.1
- Streak
- white to pale brown
- Lustre
- adamantine (diamond-like), submetallic, greasy
- Crystal system
- Tetragonal
- Colours
- brown, black, yellow, red-brown, grey, colourless
- Transparency
- transparent, translucent, opaque
- Cleavage and fracture
- imperfect; subconchoidal to uneven fracture
Typical values: real specimens vary. For more, see mindat.org.