Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Conchoidal, Brittle
ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Al 4(Ta,Nb) 3(O,OH,F) 14Ulrich Henn and Claudio C.