Ilmenite, haematite and TiO2 minerals. Derbyshire, Britain
125µm
Relict cores of ilmenite (brown, centre) are enclosed in a fine-grained Mixture of TiO2 minerals and haematite. The TiO2 rich minerals have a lower reflectance and lilac-blue colour against the haematite-rich phase (cream-white, top centre). Secondary acicular haematite (white, bottom centre) forms a small aggregate, has a higher reflectance and is whiter than haematite pseudomorphing ilmenite. Euhedral pyroxene (pale grey, top centre, right centre) and plagioclase (dark grey and featureless) are the main silicates.
Polished block, plane polarized light, x 160, oil