ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Uneven, Gems, Sixth Edition (2006)
SiO 2 + H 2OUlrich Henn and Claudio C.
(Na,K)AlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)