Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Uneven
ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Zn 2SiO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
ZrO 2Arthur Thomas , Gemstones (2009)