Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Conchoidal, Conchoidal, Handbook of mineralogy (2001)
(Fe,Mn)Ta 2O 6Walter Schumann , Gemstones of the world (2001) More from other references
(Mg,Fe2+ ) 3Si 2O 5(OH) 4Anthony et al , Handbook of mineralogy (2001)