This salt contains less sodium chloride than commercial sea salt (86% sodium chloride vs. 99.99%). Thank you rachel for this information about salt . I knew that refining was bad but didn't know to what extent . Are you sure about 86 % ? i thought he will be more than that. Would you have the exact composition of 14 % left. If the brand name celtic salt comes from "les marais de guerande" in the south of britanny ( France) i know the place . It is salt marches that have been digged out and dikes were built to make lot of different basins . The tides fill the basins and after closing the dikes are left to dry . Then the salt is scrapped with long wooden rakes. That way the salt is mixed with little bit of everything that is in thoses muddy flat. That explain the high mineral content other than sodium chloride, and the gray color. In france i was using this one but when i moved here ,before i found celtic salt i used rock salt from Utah ( unrefined mined salt from old marine deposit ) it have little bit of a red dots in it that is the red clay of utah. Celtic salt is way tastier and before i found it i was prefering to drink sea water to fulfill my special sodium needs . jean-claude