Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Perfect on {100}, imperfect on {001}
Perfect on {110} at 56° and 124°; partings on {010} and {100}
PbCu(SO 4)(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006)
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.