Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009)
Gems, Sixth Edition (2006), Gems, Sixth Edition (2006)
Na 4AlBeSi 4O 12ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
SiO 2Michael OâDonoghue , Gems, Sixth Edition (2006)