Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.90-2.982.90-3.10
1
7.18
👆🏻
Fracture
Conchoidal, ConchoidalWalter Schumann
Splintery, Granular
Cleavage
Distinct on {11 2 0}, imperfect on {10 1 1}
None
Mohs Hardness
7.5-86-6.5
2
10
👆🏻
Chemical Composition
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references