UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
BaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
3CaAl 2Si 2O 8 · CaCO 3Anthony et al , Handbook of mineralogy (2001)