Ilmenite, spinel and haematite. Derbyshire, Britain
Parallel ilmenite laths (pale brown, left) arc intergrown with plagioclase (dark grey and featureless) and pyroxene (bottom left) showing orange-brown internal reflections due to the presence of fine-grained haematite/limonite. A large pseudomorphed olivine (orange internal reflections, right) encloses euhedral small spinel crystals (brown-grey, centre right) and haematite (white, right centre) growing along a fracture. Very fine-grained haematite and limonite form the margin to the olivine and show faint red internal reflections (bottom centre). Fine-grained anatase shows abundant light-coloured internal reflections (centre left), and is associated with titanaugite.
Polished block, plane polarized light, x 160, oil