Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Conchoidal, Metallic, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
{???} Distinct, {???} Indistinct
Fair in four directions forming octahedrons
3CaAl 2Si 2O 8 · CaCO 3Anthony et al , Handbook of mineralogy (2001)
Cu 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references