Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.50-2.802.97-3.03
1
7.18
👆🏻
Fracture
-
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
Perfect
{001} Poor
Mohs Hardness
5-6.57
2
10
👆🏻
Chemical Composition
Na 4(Al,Si) 12O 24Cl to Ca 4(Si,Al) 12O 24(CO 3,SO 4)Arthur Thomas , Gemstones (2009)
CaB 2(SiO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references