Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Conchoidal, Metallic, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Mg 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006)
Cu 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references