Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
(Cs,Na)(AlSi 2O 6) · 0.5H 2OWalter Schumann , Gemstones of the world (2001) More from other references
(Ca,Mg,Mn)SiO 3Gemdat.org , Management Team (2012)