Irregular/uneven, UnevenAnthony et al, Handbook of mineralogy (2001), Brittle, Uneven
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Perfect on {110} and {1 1 0}
{110} Perfect, {110} Perfect
CaAl 2Si 3O 10 · 3H 2OUlrich Henn and Claudio C.
(Fe,Mn) 7Si 7O 21Ulrich Henn and Claudio C.