Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
3.49-3.572.90-2.98
1
7.18
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Fracture
Subconchoidal, Uneven, Conchoidal
Conchoidal, ConchoidalWalter Schumann
Cleavage
[001] Perfect
Distinct on {11 2 0}, imperfect on {10 1 1}
Mohs Hardness
87.5-8
2
10
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Chemical Composition
Al2SiO4(F,OH)2
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references