Uraninite, galena and chalcopyrite. Tyndrum, Scotland
Distinctly botryoidal uraninite shows growth zones with different reflectances and surface colours (top). It encloses abundant anhedral galena (white, top) inclusions. Present in the gangue are small chalcopyrite (yellow, top left) inclusions. Locally, the gangue shows red internal reflections (top right) due to the presence of very fine-grained haematite.
Polished thin section, plane polarized light, x 160, oil