UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
BaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references