Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.90-2.982.90-3.10
1
7.18
👆🏻
Fracture
Conchoidal, ConchoidalWalter Schumann
Uneven, Conchoidal
Cleavage
Distinct on {11 2 0}, imperfect on {10 1 1}
Poor/indistinct on {1120} and {1011}
Mohs Hardness
7.5-87
2
10
👆🏻
Chemical Composition
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) More from other references