Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
Uneven
PbCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Fe2+ ,Mg)Al 2(PO 4) 2(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006)