The manufacturing process of ocher ends in the factory with a 15-minute long calcination of natural ocher at 1472-1652°F (800-900°C). It allows obtaining hematite (red ocher) and is followed, after cooling, by the grinding and bagging phases. The ochres extracted from the different deposits are mixed to obtain different shades and are subjected to a comprehensive analysis for heavy metals and nanoparticles to ensure their certification.