Conchoidal, Brittle, Conchoidal
Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Good on [110] and on [001]
[001] good, [210] distinct
[ ]Na2(Mg3Al2)Si8O22(OH)2
PbSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references