Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Sub-Conchoidal, Irregular/uneven, Uneven, Conchoidal
[100] Perfect, [110] Good, [011] Distinct
(Li,Na)Al(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references