Tellurobismutite, tetradymite and galena. Clogau Mine, Wales, Britain
125µm
Tellurobismutite (white, right) has higher reflectance than tetradymite (green-blue, left). Galena (blue-grey, centre) inclusions occur at the junction of the two tellurium-bearing minerals. Black areas are quartz.
Polished block, plane polarized light, x 160, oil
