Stromeyerite, bornite, galena, chalcocite and tetrahedrite group mineral and pyrite. Unknown Provenance
Inclusion-free galena (white, centre right) is intergrown with bornite (brown, top) and stromeyerite, showing purple-grey (left centre) to blue-grey (bottom centre) reflection pleochroism. Stromeyerite occurs in a symplectite-like intergrowth with chalcocite (light blue, centre, bottom right) which is accentuated in the section by relief differences. Subhedral tetrahedrite (green-grey, moderate reflectance, centre left, extreme bottom right) is pitted and is associated with euhedral quartz (dark grey, centre left). Pyrite (light yellow-white, high reflectance, centre) is subhedral to euhedral.
Polished block, plane polarized light, x 80, air