Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Conchoidal, UnevenArthur Thomas, Brittle
(Mg,Fe) 5(SiO 4) 2(F,OH) 2Ulrich Henn and Claudio C.
Fe2+ CO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references