Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009)
BaSO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Mg,Fe2+ )Al 2O 4Gemdat.org , Management Team (2012) More from other references