Uneven, Brittle, Metallic, Brittle, Metallic, Brittle, Metallic
Conchoidal, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Brittle, Metallic
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.
CaBSiO 4(OH)Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references