Tenacity
-
Brittle
Solubility
-
insoluble in water
Durability
-
-
Specific Gravity
2.90-3.105.00-5.20
1
7.18
👆🏻
Fracture
Uneven, Conchoidal
Uneven, Conchoidal, ConchoidalWalter Schumann
Cleavage
Poor/indistinct on {1120} and {1011}
Indistinct on {001}; partings on {011} and {111}
Mohs Hardness
76-6.5
2
10
👆🏻
Chemical Composition
Na(Li 1.5Al 1.5)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012) More from other references
FeS 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references