Tenacity
Brittle
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.772.79-2.87
1
7.18
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Fracture
Uneven
Conchoidal
Cleavage
Perfect [001] good [010] poor [110]
{010} perfect; {100} good, interrupted; {101} indistinct; {001} in traces
Mohs Hardness
6-6.55.5-6
2
10
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Chemical Composition
CaAl 2Si 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
NaBePO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references