ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Yellow, White, UnevenWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Metallic
(K,Cs)Al 4Be 4(B,Be) 12O 28Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca2Al2Si3O12(OH)