UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
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