Magnetite and ilmenite. Derbyshire, Britain
Euhedral magnetite (light brown, centre) carries abundant ilmenite lamellae (darker brown) oriented along (111) and the result of oxidation-exsolution. An incomplete magnetite rim around the euhedral crystal also carries exsolved ilmenite (centre right). Very small grains of tarnished bornite (red-brown, centre right) have replaced original chalcopyrite. Euhedral to subhedral pyroxene (light grey, left) and plagioclase (dark grey, light internal reflections, bottom right) are the main silicate phases. Minor amounts of relict carbon-coating are blue-grey (bottom centre).
Polished block, plane polarized light, x 160, oil