1 Physical Properties
1.1 Tenacity
Not Available
Not Available
1.2 Solubility
Not Available
Not Available
1.3 Durability
1.4 Specific Gravity
1.5 Fracture
Uneven, Conchoidal, UnevenWalter Schumann, Gemstones of the world (2001)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
1.6 Cleavage
Perfect {010}, imperfect {100}
Good on {100}
1.7 Mohs Hardness
1.8 Chemical Composition
Ca2Al3(SiO4)3(OH)
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references