Chalcopyrite, pyrite and sphalerite. Çeyeli, Turkey
Pyrite (pale yellow-white, high reflectance) forms euhedral crystals with thin chalcopyrite rims (bottom right) and is extensively replaced by chalcopyrite (yellow, centre right) in a characteristic texture found in many volcanogenic deposits. Euhedral to subhedral sphalerite (light grey) overgrows chalcopyrite (right centre).
Polished block, plane polarized light, x 80, air