Minerals
Topaz
Al2SiO4(F,OH)2
Géry PARENT / CC BY-SA 3.0, via Wikimedia Commons · CC BY-SA 3.0 · Source
Overview
Hard nesosilicate; perfect basal cleavage.
Identification characteristics
- Mohs hardness 8
- Streak: White
- Lustre: Vitreous
Formation and occurrence
Pegmatites, rhyolites
Common uses
Gemstone