Tourmaline is one of the later innovations in plates for hair straighteners. This new material is made of a crystal that gets ground into dust and then applied to the plates of the straightening iron. Tourmaline is able to produce negative ions while straightening, and the presence of those ions makes it possible to straighten hair with less heat. The negative ions actually trap moisture into the hair, combining reduced heat with a higher moisture level to make hair look shiny. Tourmaline irons are more expensive than other alternatives, but they work much faster than their older counterparts.