Sphalerite, galena, chalcopyrite, tetrahedrite group mineral and bournonite. Broken Hill, New South Wales, Australia
Sphalerite (light grey, centre) is intergrown with galena (white, centre left). Chalcopyrite (yellow, centre top) forms an incomplete rim to sphalerite and is associated with bournonite (white rim to chalcopyrite, centre top) and tetrahedrite (white, centre top right). At this magnification, galena, tetrahedrite group minerals and bournonite cannot easily be distinguished in plane polarized light. Dark grey area is gangue.
Polished block, plane polarized light, x 40, air