ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, ConchoidalWalter Schumann, Gemstones of the world (2001)
CaZrBAl 9O 18Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
SiO 2Ulrich Henn and Claudio C.