Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
Irregular/uneven, UnevenArthur Thomas, Gemstones (2009)
(Ca,Ce) 4 Na(Na,Ca) 2 Ti(Si 2 O 7 ) 2 F 2 (O,F) 2 Michael O’Donoghue, Gems, Sixth Edition (2006)
CaAl 2Si 4O 12 -6H 2OArthur Thomas , Gemstones (2009)