ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
CaTiSiO 5Ulrich Henn and Claudio C.
Na 2(Ti,Fe)Si 4(O,F) 11Ulrich Henn and Claudio C.