Tenacity
Brittle
Brittle
Solubility
-
Soluble
Durability
-
-
Specific Gravity
3.53-3.653.30-3.50
1
7.18
👆🏻
Fracture
Splintery
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
[100] perfect [010] imperfect with 79° angle between
Perfect on {110}, poor on {101}, {001} rare
Mohs Hardness
4-75
2
10
👆🏻
Chemical Composition
Al2SiO5
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references