Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Perfect on {110}, poor on {101}, {001} rare
Perfect on {110} at 56° and 124°; partings on {010} and {100}
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.