Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001)
Na 2(Ti,Fe)Si 4(O,F) 11Ulrich Henn and Claudio C.
Ca 2 MgAl 2 BSi 4 O 15 OH Gemdat.org, Management Team (2012)