Tenacity
Brittle
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
3.69-3.812.77
1
7.18
👆🏻
Fracture
Uneven, Conchoidal to uneven, ConchoidalWalter Schumann
Uneven
Cleavage
Distinct on {110}, imperfect on {010}, poor on {001}
Perfect [001] good [010] poor [110]
Mohs Hardness
8.56-6.5
2
10
👆🏻
Chemical Composition
BeAl 2 O 4
CaAl 2Si 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)