Tenacity
Brittle
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
1.792.72-2.75
1
7.18
👆🏻
Fracture
Irregular/uneven
Uneven
Cleavage
Perfect on {10bar10}
Perfect on [001], good on [010], imperfect on [110]
Mohs Hardness
2.56-6.5
2
10
👆🏻
Chemical Composition
Ca6(Al,Si)2(SO4)2B(OH)4(OH,O)12•26(H2O)
Ca(70-90%)Na(30-10%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)