Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.265.5
1
7.18
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Fracture
Uneven
Conchoidal
Cleavage
None
{111} Indistinct, {111} Indistinct, {111} Indistinct
Mohs Hardness
-99995-5.5
2
10
👆🏻
Chemical Composition
NaFe3+3Fe3+6(BO 3) 3Si 6O 18(O,OH) 4Anthony et al , Handbook of Mineralogy (2001)
(Ca,Na) 2Ta 2O 6(O,OH,F)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references