Pyrrhotite, altered pyrrhotite, chalcopyrite, violarite and pentlandite. Bushveld, Republic of South Africa
Pyrrhotite (brown-pink, right) enclosing chalcopyrite (yellow) has a larger pentlandite (brown, higher reflectance) crystal on its right hand margin. An original chalcopyrite, pyrrhotite and pentlandite intergrowth (left) now comprises unaltered chalcopyrite (yellow, left centre), very fine-grained alteration products after pyrrhotite the so called zwischen-produkt (white with cleavage, centre left) and violarite (dark brown and poorly polished, centre bottom) after pentlandite. Grey areas are silicate phases, black areas are polishing pits.
Polished block, plane polarized light, x 80, air