UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Conchoidal
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
PbCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references