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