Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
Uneven, Uneven, Gemstones of the world (2001) More from other references
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references