Pyrrhotite, pyrite, magnetite and chalcopyrite. Ducktown, Tennessee, USA
Subhedral to euhedral magnetite (light grey, centre left) encloses rounded pyrrhotite (brown) inclusions. Pyrite (yellow-white, bottom right) is enclosed within pyrrhotite (brown) which shows metamorphic cleavage (top right), some of this cleavage penetrates pyrite (top left, centre bottom). Thin rims of chalcopyrite (yellow, bottom centre) surround pyrite and magnetite. Black areas are polishing pits.
Polished block, plane polarized light, x 40, air