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