Tenacity
Brittle
-
Solubility
Soluble
-
Durability
-
-
Specific Gravity
3.30-3.503.03-3.18
1
7.18
👆🏻
Fracture
Uneven, ConchoidalWalter Schumann, Conchoidal
Uneven, Irregular, Conchoidal
Cleavage
Perfect on {110}, poor on {101}, {001} rare
{???} Indistinct
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
Na(Mg 3)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)