Is the term 'sea salt' redundant?

It's not so much "redundant" as "meaningless". There is no FDA regulation on salt. You can call pretty much anything "sea salt". "Sea salt" implies, but does not prove, that the salt was minimally processed from evaporated ocean water. Therefore it contains all of the "minerals" found in that patch of ocean. read more

The salt that is mined from the earth IS sea salt, it's just produced by natural methods and aged (for example, the Great Salt Lake's salt flats are the remnants of an inland sea. The sea was cut off from its water supply and exit to the oceans and evaporated. read more