I want burning salts. I don't know if there are such a thing, but I want something, chemical sand perhaps, that, when tossed into a normal fire, makes it burn a different color. Wouldn't glowing purple flames be so cool?

I was kinda hoping to leave chemicals out of this. I mean, I realize that the product would have chemicals in it, but that being said. I was more looking for a product than the chemicals I should be stealing (cause I happen to have tons of Borax just lying around, right?)