1 Physical Properties
1.1 Tenacity
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
3.26-3.362.72-2.75
1
7.18
1.5 Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, Gems, Sixth Edition (2006)
1.6 Cleavage
Good on {100}
Perfect on [001], good on [010], imperfect on [110]
1.7 Mohs Hardness
1.8 Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
Ca(70-90%)Na(30-10%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)