Most ordinary salt is rock salt, the residue of ancient oceans mined from underground, which comes finely ground or in large crystals. Some cooks prefer to use coarse rock or sea salt (which has been evaporated from sea water, or from salt marshes), as these do not need the anti-caking additives used in many brands of finely ground salt. Sea salt is a good choice for both cooking and the table. One of the finest is Maldon salt from Essex, in England, with large soft flakes that can be crushed by the fingers.
** Asian Recipes