Irregular/uneven, UnevenArthur Thomas, Gemstones (2009)
ConchoidalGemdat.org, Management Team (2012), ConchoidalGemdat.org, Management Team (2012)
CaAl 2Si 4O 12 -6H 2OArthur Thomas , Gemstones (2009)
(Fe,Mg) 3Al 2(SiO 4) 3gemdat.org , Management Team (2012)