Handbook of mineralogy (2001)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Na x[Fe2+2(Al,Fe3+ )]Al 6(BO 3) 3Si 6O 18(OH) 4Anthony et al , Handbook of mineralogy (2001)
Pb 5(AsO 4) 3ClMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references