Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle
Subconchoidal, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Zn 2(AsO 4)(OH) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Na 3(Na,K)Al 4Si 4O 16Ulrich Henn and Claudio C.