UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
Zn 2(AsO 4)(OH) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references