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