Tenacity
-
Brittle
Solubility
insoluble in water
Soluble
Durability
-
-
Specific Gravity
3.62-3.873.30-3.50
1
7.18
👆🏻
Fracture
Conchoidal
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
None
Perfect on {110}, poor on {101}, {001} rare
Mohs Hardness
7-7.55
2
10
👆🏻
Chemical Composition
Mg 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references