ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Uneven, Conchoidal, Brittle, Metallic, ConchoidalArthur Thomas, Gemstones (2009)
Na 2Ca 2(CO 3) 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca 3Cr 2(SiO 4) 3Ulrich Henn and Claudio C.