Conchoidal, Brittle, Conchoidal, Brittle, Conchoidal, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Conchoidal
ConchoidalWalter Schumann, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle, Metallic
[001] good, [210] distinct
Perfect on {010}, good on {100}
PbSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
Be 2BO 3(OH)Ulrich Henn and Claudio C.