Uneven, Conchoidal, UnevenWalter Schumann, Gemstones of the world (2001)
ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Ca2Al3(SiO4)3(OH)
(Cs,K,Rb)Al 4Be 4(B,Be) 12O 28Anthony et al , Handbook of mineralogy (2001)