Pyrite, native gold and galena. Clogau Mine, Wales, Britain
Pyrite (light yellow-white, centre) is associated with native gold (yellow, high reflectance, centre left) and galena (grey-white, low reflectance, top right, left centre). The perceived surface colour of pyrite and galena is unaffected by the presence of the gold. Quartz is the main gangue. The gold is 800 fine.
Polished block, plane polarized light, x 80, air