Stromeyerite, bornite, tetrahedrite group mineral and pyrite. Unknown Provenance
Euhedral pyrite (light yellow-white, top left) and subhedral tetrahedrite (green-grey, centre) are harder than bornite (brown, top) and stromeyerite (pink-grey to blue-grey, bottom right). Stromeyerite shows faint bireflectance and reflection pleochroism from pink-grey (centre right) to blue grey (bottom right). Black areas are polishing pits.
Polished block, plane polarized light, x 80, air