Uneven, UnevenArthur Thomas, Gemstones (2009), Splintery
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Uneven
Ca 2(Mg,Fe) 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
Mn 3B 7O 13ClMichael OâDonoghue , Gems, Sixth Edition (2006)