Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
(Ca,Ce) 4 Na(Na,Ca) 2 Ti(Si 2 O 7 ) 2 F 2 (O,F) 2 Michael O’Donoghue, Gems, Sixth Edition (2006)
Subconchoidal, ConchoidalWalter Schumann, Conchoidal
Perfect on {001}, poor on {201} with 38.5° angle between the two
LiAlSi 4O 10Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references