Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
3.43-3.442.33-2.37
1
7.18
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Fracture
-
ConchoidalWalter Schumann
Cleavage
None Observed
Perfect on {010}, good on {100}
Mohs Hardness
6.5-77.5
2
10
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Chemical Composition
Ca 2(Mg,Al) 6(Si,Al,B) 6O 20Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Be 2BO 3(OH)Ulrich Henn and Claudio C.