Tenacity
Brittle
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.90-2.982.74-2.90
1
7.18
👆🏻
Fracture
Conchoidal, ConchoidalWalter Schumann
Uneven, Splintery
Cleavage
Distinct on {11 2 0}, imperfect on {10 1 1}
Perfect on {100} and {001}
Mohs Hardness
7.5-84.5-5
2
10
👆🏻
Chemical Composition
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca 2NaHSi 3O 9Ulrich Henn and Claudio C.