Pyrite, chalcopyrite, galena, sphalerite and tetrahedrite. Ainai Mine, Akita Prefecture, Japan
125µm
Euhedral pyrite (light yellow-white, left) is intergrown with chalcopyrite (yellow, centre), galena (light blue-white, centre right) and tetrahedrite (green-blue, lower reflectance, harder than galena, centre right) and minor sphalerite (grey, centre top). A coarse-grained subhedral crystal of sphalerite (right bottom) encloses chalcopyrite and is itself enclosed within euhedral galena. Gangue phases are black.
Polished block, plane polarized light, x 160, oil
