Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Brittle, Uneven, Brittle, Uneven
PbSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
NaCa16Si23AlO60(OH)8•64(H2O)