Subconchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Splintery, Granular, Splintery, Granular, Gemstones (2009)
(Mg,Fe2+ ) 9(SiO 4) 4(F,OH)) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
Ca 2(Mg,Fe) 5(OH) 2Walter Schumann , Gemstones of the world (2001) More from other references