Tenacity
Brittle
-
Solubility
insoluble in water
-
Durability
-
-
Specific Gravity
5.00-5.202.54-2.78
1
7.18
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Fracture
Uneven, Conchoidal, ConchoidalWalter Schumann
Conchoidal
Cleavage
Indistinct on {001}; partings on {011} and {111}
Good in three directions
Mohs Hardness
6-6.55-6
2
10
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Chemical Composition
FeS 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references