Uneven, UnevenArthur Thomas, Gemstones (2009), Splintery
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Ca 2(Mg,Fe) 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
Pb 5(AsO 4) 3ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references