Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle
Conchoidal, ConchoidalAnthony et al, Conchoidal, Brittle, Conchoidal
Na 2(Ti,Fe)Si 4(O,F) 11Ulrich Henn and Claudio C.
(Zn,Cu)Al 6(PO 4) 4(OH) 8 · 4H 2OMichael OâDonoghue , Gems, Sixth Edition (2006)