If that isn't a fantastically deceptive piece of marketing then I don't know what is. It writes as if other salt deposits didn't originate in some kind of ancient body of water, and it uses the fact that they're harvesting a brine to imply that the entire bloody ocean is still hiding under the Appalachians, so that by buying their salt you're buying "sea salt" (and all the naturalist voodoo that might entail) but without any of the contaminants of modern oceans. Being low in mercury and whatnot seems like a good thing, and their salt is probably fine, but that marketing is something else.

'normal' salt mined from the ground don't have microplastics in it,