ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Subconchoidal, Uneven, Subconchoidal, Splintery, UnevenArthur Thomas, Gemstones (2009)
Mg 3(Al,Cr) 2(SiO 4) 3Gemdat.org , Management Team (2012)
Al 2SiO 5Michael OâDonoghue , Gems, Sixth edition (2006) More from other references