Conchoidal, Metallic, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Cu 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Fe 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)