Pyrrhotite, sphalerite, chalcopyrite and galena. Unknown Provenance
Pyrrhotite shows bireflectance and reflection pleochroism from brown to light brown-yellow (bottom left). The differences in polishing between pitted and well polished pyrrhotite grains reflect different crystal orientations of the pyrrhotite. Sphalerite (light grey, centre right), chalcopyrite (yellow, centre) and galena (white, top centre) form incomplete margins about pyrrhotite. Dark grey phases are tabular metamorphic silicates. The uniform grain size of the pyrrhotite shows it to have recrystallized.
Polished block, plane polarized light, x 80, air