Pyrrhotite, sphalerite, chalcopyrite and galena. Unknown Provenance
Pyrrhotite crystals (brown) show bireflectance and reflection pleochroism (light brown to darker brown, centre). They are equidimensional and have triple junctions which suggest they have recrystallized. Inclusion-free sphalerite (light grey, bottom) is intergrown and encloses a grain of galena (white, bottom right) and chalcopyrite (top centre).
Polished block, plane polarized light, x 80, air