UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Uneven
Uneven, Uneven, Gems, Sixth Edition (2006), Uneven, Conchoidal
FeS 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
NaAlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)