Sphalerite, chalcopyrite, pyrite, bornite and galena. Çeyeli, Turkey
Concentrically banded bornite (brown, centre) and chalcopyrite (yellow, centre) are intergrown with poorly crystalline pyrite (pale yellow-white, centre top) which shows variations in reflectance and surface colour due to differences in crystallinity (top left) and degree of replacement by chalcopyrite (bottom left). Coarse-grained chalcopyrite (centre bottom) is intergrown with galena (blue-white, centre bottom) about sphalerite (light grey, centre), which is free of fine-grained inclusions. Silicates and sulphates (dark greys) constitute the gangue.
Polished block, plane polarized light, x 80, air