Sphalerite, pyrrhotite, chalcopyrite and galena. Unknown Provenance
Sphalerite (light grey) is intergrown with pyrrhotite (brown) which shows reflection pleochroism and bireflectance (bottom left) and the effects of orientation on polishing characteristics (centre and bottom left). Anhedral chalcopyrite (yellow, top centre) and galena (white, top centre) commonly surround pyrrhotite. Dark grey areas are quartz and metamorphic silicates.
Polished block, plane polarized light, x 80, air