Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.90-2.982.50-2.80
1
7.18
👆🏻
Fracture
Conchoidal, ConchoidalWalter Schumann
-
Cleavage
Distinct on {11 2 0}, imperfect on {10 1 1}
Perfect
Mohs Hardness
7.5-85-6.5
2
10
👆🏻
Chemical Composition
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Na 4(Al,Si) 12O 24Cl to Ca 4(Si,Al) 12O 24(CO 3,SO 4)Arthur Thomas , Gemstones (2009)