Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Mg 2Al 4Si 5O 18Ulrich Henn and Claudio C.
Cu 3(OH) 2(CO 3) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references