I've heard that too. I've seen several varieties of salt in supermarkets: table salt, sea salt, iodized salt, rock salt etc. I know there is a nutritional difference between sea salt and mined salt but I'm not certain on the exact details. Hmm, I should look it up.
In my journey of self-discovery I was surprised that I'm pretty sensitive about the texture of my food. I was eating rice and the moment I felt a hard bit, like a tiny rock, my throat seized up and I involuntarily ejected everything in my mouth. Not sure why it happened, it's probably all in my head, it's weird. Which is why I'm not a fan of rock salt (the stuff you have to manually grind) because it sometimes results in several tiny bits that just irk my mouth.
