Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
Uneven, ConchoidalArthur Thomas, Brittle, Metallic
(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)
Pb 5(PO 4) 3ClArthur Thomas , Gemstones (2009)