Sphalerite, galena and pyrite. Navan, Ireland
250µm
Galena (blue-white, left) is overgrown by botryoidal sphalerite (light grey), which in turn has a botryoidal pyrite rim (yellow-white, centre). Coarse-grained carbonate (dark grey, centre) is the main gangue. Black areas are polishing pits.
Polished block, plane polarized light, x 80, air
