Tenacity
-
Brittle
Solubility
-
insoluble in water
Durability
-
-
Specific Gravity
2.27-2.335.00-5.20
1
7.18
👆🏻
Fracture
-
Uneven, Conchoidal, ConchoidalWalter Schumann
Cleavage
Perfect
Indistinct on {001}; partings on {011} and {111}
Mohs Hardness
5.5-66-6.5
2
10
👆🏻
Chemical Composition
Na 8Al 6Si 6O 24Cl 2Michael OâDonoghue , Gems, Sixth Edition (2006)
FeS 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references