Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
(Mg,Fe2+ ) 2(Mg,Fe2+ ) 5Si 8O 22(OH) 2Anthony et al , Handbook of mineralogy (2001)
MgAlBO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references