UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle
Ca 2B 5SiO 9(OH) 5Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Zn 2(AsO 4)(OH) · H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references