Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.79-2.872.65
1
7.18
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Fracture
Conchoidal
ConchoidalWalter Schumann
Cleavage
{010} perfect; {100} good, interrupted; {101} indistinct; {001} in traces
None
Mohs Hardness
5.5-67
2
10
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Chemical Composition
NaBePO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
SiO 2Walter Schumann , Gemstones of the world (2001)