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