Uneven, Uneven, Gems, Sixth Edition (2006)
Uneven, Uneven, Conchoidal, Uneven, Gems, Sixth Edition (2006)
From the Greek for oblique and fracture, descriptive of the cleavage
Perfect on {001}, good on {010}
(Na,K)AlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
(Na,Ca)Al1-2Si3-2O8