Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.90-3.102.90-2.98
1
7.18
👆🏻
Fracture
Uneven, Conchoidal
Conchoidal, ConchoidalWalter Schumann
Cleavage
Poor/indistinct on {1120} and {1011}
Distinct on {11 2 0}, imperfect on {10 1 1}
Mohs Hardness
77.5-8
2
10
👆🏻
Chemical Composition
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
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references