Tenacity
Brittle
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
2.72-2.755.6-5.76
1
7.18
👆🏻
Fracture
Uneven
Uneven
Cleavage
Perfect on [001], good on [010], imperfect on [110]
[001] perfect; [100] distinct
Mohs Hardness
6-6.52.5-3
2
10
👆🏻
Chemical Composition
Ca(70-90%)Na(30-10%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
Pb 5Cu 2(SO 4) 3(CO 3)(OH) 6Anthony et al , Handbook of mineralogy (2001)