Uneven, Conchoidal, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle
Not Available
FeS 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Ce,La,Nd,Th)PO 4Michael OâDonoghue , Gems, Sixth Edition (2006)