Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Mg 2Si 2O 6Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
NaBePO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references