Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
1.98-2.505.00-5.30
1
7.18
👆🏻
Fracture
Conchoidal
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
None
None, may show partings on {0001} and {10 1 1}
Mohs Hardness
5.5-6.56
2
10
👆🏻
Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Fe 2O 3Arthur Thomas , Gemstones (2009)