Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
Handbook of mineralogy (2001)
Na 2(Ti,Fe)Si 4(O,F) 11Ulrich Henn and Claudio C.
Na x[Fe2+2(Al,Fe3+ )]Al 6(BO 3) 3Si 6O 18(OH) 4Anthony et al , Handbook of mineralogy (2001)