ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Uneven
Brittle, Metallic
(Mn2+ ,Fe2+ ,Mg,Ca) 2(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth Edition (2006)
◻(LiAl 2)Al 6(Si 6O 18)(BO 3) 3(OH) 3(OH)Gemdat.org , Management Team (2012)