Galena, cerussite and anglesite. South Pennines, Britain
Galena (white, top) shows well developed plucking along (100) to give characteristic triangular pits (black). It is altered and replaced by rhythmical aggregates of cerussite (light greys) showing faint bireflectance (bottom left) and anglesite (lower reflectance, poorly polished bands, centre right). This is a fine example of a caries texture. Smaller crystals of galena are totally pseudomorphed by cerrussite and anglesite (bottom). Dark grey areas are fluorite, black areas are polishing pits.
Polished block, plane polarized light, x 80, air