Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Uneven, Uneven, Gems, Sixth Edition (2006), Uneven, Conchoidal
Perfect on [10 1 1] three directions with angle of 74° 55
Perfect on {001}, very good on {010}, imperfect on {110}
CaCO 3Ulrich Henn and Claudio C.
NaAlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)