Uneven
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
(Mg,Fe2+ ) 5Al(Si 3Al)O 10(OH) 8Anthony et al , Handbook of mineralogy (2001)
KNa 2(Fe3+ ,Mn3+ ,Al) 2Li 3Si 12O 30Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references