Subconchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Uneven
(Ca,Ce)(Al,Ti,Mg)12O19
(Al,Mg) 8(Al,Si) 6O 20Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references