Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
1.98-2.502.33-2.37
1
7.18
👆🏻
Fracture
ConchoidalWalter Schumann
ConchoidalWalter Schumann
Cleavage
None
Perfect on {010}, good on {100}
Mohs Hardness
5.5-6.57.5
2
10
👆🏻
Chemical Composition
SiO 2 · nH 2OWalter Schumann , Gemstones of the world (2001)
Be 2BO 3(OH)Ulrich Henn and Claudio C.