UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
MgAlBO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references