UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Uneven
Subconchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Irregular
FeS 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
SnO 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references