Galena, chalcopyrite, enargite, covelline and sphalerite. Clevedon, Somerset, Britain
45µm
Galena (blue-white, top) has a rim of chalcopyrite (yellow, centre right) which is partly altered to covelline laths (red, centre right) growing into a vug. Euhedral enargite (centre) is zoned from a lower reflectance (blue-grey) core to brown margin. Minor sphalerite (grey, centre top) occurs between chalcopyrite and enargite but also overgrows enargite into the vug (centre); this is difficult to see (grey with faint internal reflections). Gangue minerals below the surface of the section in the vug show strong internal reflections.
Polished block, plane polarized light, x 450, oil
