Not Available
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
CaAlB 3O 7Michael OâDonoghue , Gems, Sixth Edition (2006)
(Ca,Mn2+ )Si 3O 9Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references