UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
Mg 2Si 2O 6Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references