Uneven, Splintery, Conchoidal, Uneven, Splintery, Conchoidal, UnevenWalter Schumann, Gemstones of the world (2001)
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
SiO 2Arthur Thomas , Gemstones (2009)
Cu 3(OH) 2(CO 3) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references