The bottom of the salt pan () is typically composed of clay lined pools, basalt, sand, concrete, or tile. This keeps the salt from coming into contact with the silt beneath and becoming dirty. Every few days, or on occasion daily, the harvester (French: ) pushes or pulls the salt with a long wooden rake. This must be done carefully as the depth of the brine may be as little as  and the clay bottom must not be penetrated at the risk of contaminating the salt. The salt is raked toward the sides of the pan where it is then shoveled into a pile and left to dry slightly before storing.  of sel gris can be harvested in one day, whereas for fleurs de sel the daily yield is only .