Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
(K,Na)3Cu20Al3Si29O76(OH)16•~8(H2O)
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