Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009)
Irregular/uneven, UnevenArthur Thomas, Gemstones (2009)
(Mg,Fe2+ )Al 2O 4Gemdat.org , Management Team (2012) More from other references
CaAl 2Si 4O 12 -6H 2OArthur Thomas , Gemstones (2009)