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TopazAl2SiO4(F,OH)2

Class: Silicate
Hardness: 8
Density: 3.5
Streak: White
Lustre: Glassy
Habit: Prismatic crystals
Colours: Almost brownish, any colour

  Crystal System: Orthorhombic
Cleavage: Perfect
Fracture: Subconchoidal
Magnetism: None
Reaction with HCl: None

Identification in hand sample:
Resembles quartz, but harder.

Associations:
Quartz

Industrial / ecomonic uses:
Gemstone

Comments:
Forms most commonly in pegmatites.

  

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