Not Available
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Ca 2NaHSi 3O 9Ulrich Henn and Claudio C.
PbSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references