Tenacity
Brittle
-
Solubility
Soluble
insoluble in water
Durability
-
-
Specific Gravity
3.30-3.503.62-3.87
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 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)