Tenacity
Brittle
Brittle
Solubility
Soluble
Soluble
Durability
-
-
Specific Gravity
3.30-3.502.95-2.96
1
7.18
👆🏻
Fracture
Uneven, ConchoidalWalter Schumann, Conchoidal
Conchoidal
Cleavage
Perfect on {110}, poor on {101}, {001} rare
None
Mohs Hardness
57-7.5
2
10
👆🏻
Chemical Composition
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Mg 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references