Tenacity
Brittle
-
Solubility
Soluble
-
Durability
-
-
Specific Gravity
3.30-3.502.50-2.80
1
7.18
👆🏻
Fracture
Uneven, ConchoidalWalter Schumann, Conchoidal
-
Cleavage
Perfect on {110}, poor on {101}, {001} rare
Perfect
Mohs Hardness
55-6.5
2
10
👆🏻
Chemical Composition
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Na 4(Al,Si) 12O 24Cl to Ca 4(Si,Al) 12O 24(CO 3,SO 4)Arthur Thomas , Gemstones (2009)