UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009)
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
KNa 2(Fe3+ ,Mn3+ ,Al) 2Li 3Si 12O 30Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references