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)
{110} Perfect, {110} Perfect, {110} Perfect
(Zn,Fe)SMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references