Uneven, Uneven, Conchoidal, Uneven, Gems, Sixth Edition (2006)
Gems, Sixth Edition (2006), Gems, Sixth Edition (2006), Uneven
Perfect on {001}, good on {010}
From the Greek, oligos and kasein, little cleavage.
(Na,Ca)Al1-2Si3-2O8
Na(90-70%)Ca(10-30%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)