ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
ConchoidalMichael OâDonoghue, Gems, Sixth Edition (2006), Gems, Sixth Edition (2006)
(Cs,K,Rb)Al 4Be 4(B,Be) 12O 28Anthony et al , Handbook of mineralogy (2001)
SiO2