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 in three directions
1.7 Mohs Hardness
1.8 Chemical Composition
Ca2Al3(SiO4)3(OH)
K(Ca,Na) 2Si 4O 10(OH,F) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references