Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
Conchoidal, Splintery
CaBSiO 4(OH)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
KNa 2B 3Si 12O 30Michael OâDonoghue , Gems, Sixth Edition (2006)