Black, Green, Black, Green, Black, Green, gray, Black, Green, gray
White, Colorless, Blue, Red, Green, Yellow, Violet
Not Available, Not Available, gray, Green
Not Available
Uneven, Brittle, Metallic, Brittle, Metallic
Not Available
NaNa2(Fe++4Fe+++)Si8O22(OH)2
SiO 2 (with trace Cr minerals) Gemdat.org , Management Team (2012)