Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Irregular/uneven, UnevenArthur Thomas, Gemstones (2009)
SrCO 3Walter Schumann , Gemstones of the world (2001) More from other references
CaAl 2Si 4O 12 -6H 2OArthur Thomas , Gemstones (2009)