Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
Irregular/uneven, UnevenArthur Thomas, Gemstones (2009)
Mg 3(SiO 4)(F,OH) 2Anthony et al , Handbook of Mineralogy (2001)
CaAl 2Si 4O 12 -6H 2OArthur Thomas , Gemstones (2009)