Black Salt Bath Bomb DIY

Have you ever heard of black salt?  I had not until I saw this recipe from The Soap Queen for Black Salt Bath Bomb.  IF you decide to use charcoal in this recipe, Polysorbate 80 is key in this recipe.  Polysorbate 80 is an emulsifier that helps mix the charcoal into the water, resulting in less charcoal on your skin and tub.