1 Physical Properties
1.1 Tenacity
Not Available
Not Available
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
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1.4 Specific Gravity
1.5 Fracture
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Brittle, Metallic, Brittle, Metallic
1.6 Cleavage
{111} Indistinct, {111} Indistinct, {111} Indistinct
{001} Perfect, {110} Distinct, {101} Distinct
1.7 Mohs Hardness
1.8 Chemical Composition
(Ca,Na) 2Ta 2O 6(O,OH,F)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Be 4Si 2O 7(OH) 2Anthony et al , Handbook of mineralogy (2001)