This is considered by most chefs to be the finest of all salts. Fleur de sel is a true artisan salt, consisting of only the delicate top crystals of sea salt which are hand-harvested from evaporation ponds under specific weather conditions by traditional "paludiers" (salt farmers) off the coast of Brittany in France. This salt has a grey hue due to the high level of naturally-occurring minerals. It is considered to be the purest of all salts.
Fleur de sel dissolves more quickly than regular sea salt due to the tiny crystals. It is used mainly as a finishing salt, and is sprinkled over a dish just before serving.