Tenacity
Brittle
Brittle
Solubility
-
Soluble
Durability
-
-
Specific Gravity
3.69-3.813.30-3.50
1
7.18
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Fracture
Uneven, Conchoidal to uneven, ConchoidalWalter Schumann
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
Distinct on {110}, imperfect on {010}, poor on {001}
Perfect on {110}, poor on {101}, {001} rare
Mohs Hardness
8.55
2
10
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Chemical Composition
BeAl 2 O 4
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references