Virtual Atlas of Opaque and Ore Minerals
Pentlandite, chalcopyrite, pyrite and pyrrhotite. Merensky Reef. Bushveld, Republic of South Africa
Pentlandite (light brown, centre) is intergrown with chalcopyrite (yellow, right), pyrite (pale yellow-white, centre bottom) and minor amounts of pyrrhotite (lilac-grey, centre right). Silicate gangue (grey) shows internal reflections. Black areas are polishing pits. The sulphides are interstitial to the silicates.
Polished block, plane polarized light, x 80, air