Gems, Conchoidal, Brittle
Uneven, Conchoidal, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle
Ca 3Ti4+2(Fe3+2Si)O 12Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
FeS 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references