Tenacity
Brittle
-
Solubility
Soluble
-
Durability
-
-
Specific Gravity
3.10-3.205.5
1
7.18
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Fracture
Uneven, Conchoidal
Conchoidal
Cleavage
Poor to good on (001)
{111} Indistinct, {111} Indistinct, {111} Indistinct
Mohs Hardness
6-6.55-5.5
2
10
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Chemical Composition
(Mg,Fe) 5(SiO 4) 2(F,OH) 2Ulrich Henn and Claudio C.
(Ca,Na) 2Ta 2O 6(O,OH,F)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references