Uneven, Uneven, Gemstones of the world (2001) More from other references
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
PbCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references