Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
MgCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
PbSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references