Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
From the Greek, oligos and kasein, little cleavage.
Na(90-70%)Ca(10-30%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
{111} Indistinct, {111} Indistinct, {111} Indistinct
(Ca,Na) 2Ta 2O 6(O,OH,F)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references