Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.60-3.022.90-2.98
1
7.18
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Fracture
-
Conchoidal, ConchoidalWalter Schumann
Cleavage
Perfect
Distinct on {11 2 0}, imperfect on {10 1 1}
Mohs Hardness
-99997.5-8
2
10
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Chemical Composition
(Mg,Fe2+ ) 5Al(Si 3Al)O 10(OH) 8Anthony et al , Handbook of mineralogy (2001)
Be 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references