Conchoidal, Conchoidal, Handbook of mineralogy (2001)
Uneven, UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
(Mg,Fe2+ ) 3Si 2O 5(OH) 4Anthony et al , Handbook of mineralogy (2001)
(Na,Ca) 8Al 6Si 6O 24(SO 4,S,Cl) 2Ulrich Henn and Claudio C.