Not Available
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
ZrO 2 + CaO or Y 2O 3 or MgOUlrich Henn and Claudio C.
PbSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references