Sphalerite, chalcopyrite, tetrahedrite, galena and pyrite. Ainai Mine, Akita Prefecture, Japan
Coarse-grained sphalerite (light grey, centre) crystals carry tetrahedrite (green-grey, bottom centre), chalcopyrite (yellow, centre) and galena (white, centre) inclusions. Many of the inclusions can be seen to be associated with crystal boundaries of the sphalerite; this is especially true of fine-grained tetrahedrite (left centre). Chalcopyrite, galena and pyrite form incomplete rims around sphalerite (top left), where most of the pyrite has been replaced by galena (right centre). Much of the tabular gangue (grey, top centre) is baryte. Galena looks blue and darker against pyrite (right centre) but white and lighter against tetrahedrite within sphalerite (centre).
Polished block, plane polarized light, x 80, air