Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
Subconchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Conchoidal, Brittle
KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
(Ca,Ce)(Al,Ti,Mg)12O19