Sphalerite, stannite, chalcopyrite, marcasite and galena. Nigadoo River, New Brunswick, Canada
Sphalerite (grey) has very fine chalcopyrite inclusions along its grain boundaries (bottom left) and a discontinuous veinlet of stannite (green-grey, centre) and chalcopyrite (yellow, centre left), some of which is intergrown with galena (white, centre left). Minor amounts of marcasite (white, high reflectance, left centre) are intergrown with gangue along the same veinlet. Areas of sphalerite which have a faint yellow surface colour (bottom right) contain submicroscopic chalcopyrite inclusions and have suffered chalcopyrite disease.
Polished block, plane polarized light, x 80, air