Uneven, Conchoidal, Brittle, Metallic, ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Conchoidal, UnevenArthur Thomas, Brittle
Ca 3Cr 2(SiO 4) 3Ulrich Henn and Claudio C.
Fe2+ CO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references