Uneven, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Even
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Perfect {010} imperfect {100}
{110} Perfect, {010} Indistinct
Ca2Al3(SiO4)3(OH)
(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al) 2O 6Anthony et al , Handbook of mineralogy (2001)