UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
ConchoidalGemdat.org, Management Team (2012), ConchoidalGemdat.org, Management Team (2012)
Ca 2B 5SiO 9(OH) 5Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
(Fe,Mg) 3Al 2(SiO 4) 3gemdat.org , Management Team (2012)