Gems, Sixth Edition (2006), Gems, Sixth Edition (2006)
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
SiO 2Michael OâDonoghue , Gems, Sixth Edition (2006)
Ag 3AsS 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references