Conchoidal, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
Conchoidal, UnevenWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
KNa 2Li(Fe2+ ,Mn2+ ) 2Ti 2Si 8O 24Michael OâDonoghue , Gems, Sixth Edition (2006)
CaMgSi2O6