Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
Uneven
(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)
(Mg,Fe2+ ) 5Al(Si 3Al)O 10(OH) 8Anthony et al , Handbook of mineralogy (2001)