Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.90-2.983.76-3.77
1
7.18
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Fracture
Conchoidal, ConchoidalWalter Schumann
-
Cleavage
Distinct on {11 2 0}, imperfect on {10 1 1}
{110} Perfect, {110} Perfect
Mohs Hardness
7.5-85-6
2
10
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Chemical Composition
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Fe,Mn) 7Si 7O 21Ulrich Henn and Claudio C.