Cassiterite
| Colour | Brown, Black |
|---|---|
| Mohs hardness | 6–7 |
| Lustre | Adamantine to adamantine metallic, splendent; may be greasy on fractures |
| Streak | White to brownish |
| Crystal system | Tetragonal |
| Transparency | Transparent when light colored, dark material nearly opaque; commonly zoned |
| Cleavage | {100} imperfect, {110} indistinct; partings on {111} or {011} |
| Fracture | Subconchoidal to uneven |
| Chemical formula | SnO 2 |
| Specific gravity | 6.98–7.1 |
What is Cassiterite?
Cassiterite is a tin oxide mineral, SnO2. It is generally opaque, but it is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite was the chief tin ore throughout ancient history and remains the most important source of tin today. It is also a semiconductor.
How to identify Cassiterite
- Lustre: Adamantine to adamantine metallic, splendent; may be greasy on fractures.
- Hardness: Mohs 6–7 — about as hard as a steel knife.
- Streak: White to brownish.
- Habit: Tetragonal crystal system.
Cassiterite in different forms
Stones often confused with Cassiterite
Frequently asked questions
How hard is Cassiterite?
Cassiterite is Mohs 6–7 on the hardness scale.
What colour is Cassiterite?
Cassiterite is typically brown, black (Black, brownish black, reddish brown, brown, red, yellow, gray, white; rarely colorless).