Uneven, Conchoidal, UnevenArthur Thomas, Brittle
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Fe2+ CO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Pb 5(AsO 4) 3ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references