Chalcopyrite, enargite group mineral, haematite and pyrite. Los Bronces Mine, Chile
Chalcopyrite (yellow, bottom left) and an enargite group mineral (brown, top right) enclose relict crystals of haematite (blue). Subhedral pyrite (yellow-white, high reflectance, left) carries small chalcopyrite inclusions (top left). Chalcopyrite shows incipient alteration next to haematite (grey, centre top, centre bottom), which at higher magnification is seen to be bornite. Quartz (bottom left) and tourmaline (top left) are the main silicate phases. Abundant black areas are polishing pits. The relict haematite grains within enargite are in optical continuity showing that enargite has replaced haematite.
Polished block, plane polarized light, x 80, air