Virtual Atlas of Opaque and Ore Minerals
Arsenopyrite, wolframite and covelline. Cligga Head, Cornwall, Britain
Euhedral arsenopyrite (white, high reflectance, centre) is extensively altered to covelline (blue, bottom left). Wolframite (brown-grey, top right) is poorly polished with many polishing pits (black) and shows faint zoning with blue-grey cores and brown-grey margins (right centre); this is difficult to see. Dark grey areas are quartz.
Polished block, plane polarized light, x 80, air