Ocher is a clay mineral substance composed of sand (rock) and iron oxide (mineral) that can either be extracted in open pits in quarries or underground in mines. Access to the deposits is then allowed by wells, descenders, or excavations. The exploited layers have average heights of 8.2 to 22.9 ft (2.5 to 7 m) but can reach 114.8 ft (35 m). In open pits, they are compact enough not to need any consolidation.