So I don't understand salt. I know sea salt tastes the best. I've even bought some truly expensive salt from France which for some reason was called celtic salt. And I know the U.S. started adding iodide to salt for it's health benefits.
But recently I bought rock salt from Vietnam and its called natural salt. It's not exactly pure looking and was very inexpensive. What exactly did I buy? Any ideas? Should I use it in my salt grinder or is it better suited for use in a brine?