Magnetite, molybdenite, pyrite and chalcopyrite. Newry, County Down, Britain
Chalcopyrite (yellow, centre) is intergrown with euhedral pyrite (light yellow-white, high reflectance, bottom left) and magnetite (brown-grey, top centre) which carries chalcopyrite inclusions. Curved laths of molybdenite (right) show strong bireflectance and reflection pleochroism (light grey to dark brown-grey) and also carry chalcopyrite inclusions (top right). Quartz (dark grey) shows internal reflections (centre right).
Polished block, plane polarized light, x 80, air