Uneven, Uneven, Gems, Sixth Edition (2006), Uneven, Conchoidal
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Perfect on {001}, very good on {010}, imperfect on {110}
Perfect on {110} at 56° and 124°; partings on {010} and {100}
NaAlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.