Chalcopyrite, sphalerite, bornite, pyrite and covelline. East Pacific Rise, Pacific Ocean
250µm
Chalcopyrite (yellow, top) is rimmed by bornite (pink brown, centre top) and by euhedral to subhedral sphalerite (light grey, left). Minor amounts of pyrite (white, highest reflectance) occur within chalcopyrite (top left) or within the matrix (bottom, centre). Trace amounts of covelline (blue) have replaced bornite (centre top) but are difficult to see at this magnification.
Polished block, plane polarized light, x 80, air