Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Uneven
ConchoidalGemdat.org, Management Team (2012), ConchoidalGemdat.org, Management Team (2012)
ThCa 2Si 8O 20Walter Schumann , Gemstones of the world (2001) More from other references
(Cu) 3(OH) 2(CO 3) 2 + Cu 2(CO 3)(OH) 2Gemdat.org , Management Team (2012)