Uneven, Uneven, Gems, Sixth Edition (2006)
Conchoidal, Conchoidal, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
From the Greek for oblique and fracture, descriptive of the cleavage
111 (perfect in four directions)
(Na,K)AlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
C