Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Conchoidal, Conchoidal, Handbook of mineralogy (2001)
Pb 5(AsO 4) 3ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Mg,Fe2+ ) 3Si 2O 5(OH) 4Anthony et al , Handbook of mineralogy (2001)