Uneven, UnevenArthur Thomas, Gemstones (2009)
Uneven, Brittle, Metallic, Brittle, Metallic, Brittle, Metallic
Pb 26Ag 10Cu 24Cl 62(OH) 48 · 3H 2OWalter Schumann , Gemstones of the world (2001) More from other references
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.