Tenacity
-
Brittle
Solubility
-
Soluble
Durability
-
-
Specific Gravity
2.50-2.803.30-3.50
1
7.18
👆🏻
Fracture
-
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
Perfect
Perfect on {110}, poor on {101}, {001} rare
Mohs Hardness
5-6.55
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)
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references