Irregular/uneven, UnevenAnthony et al, Handbook of mineralogy (2001), Brittle, Uneven
Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009)
CaAl 2Si 3O 10 · 3H 2OUlrich Henn and Claudio C.
(Mg,Fe2+ )Al 2O 4Gemdat.org , Management Team (2012) More from other references