Ilmenite, spinel and iron-nickel alloy. Apollo 17, Lunar Sample 7018
A basalt fragment from the lunar regolith. Abundant subparallel ilmenite laths (pale brown), many of which are 'feather-like', lie within plagioclase (areas of light-coloured internal reflection, bottom right) which is intergrown with euhedral rhombic pyroxene (light grey, few internal reflections, left centre). Small euhedral equant chromite-ulvöspinel (pale brown, top left) and rounded iron-nickel alloy (white, very high reflectance, bottom left) are present in the plagioclase also. The high magnification and large variation in reflectance between the opaque phases makes accurate colour photography difficult.
Grain mount, plane polarized light, x 400, oil