Tourmaline coatings are sometimes added to the outside metal plates of hair irons to achieve maximum ionic effect. Tourmaline gem stones come in a wide variety of colors. The name comes from the Sinhalese word "turamali" or "toramalli", which applied to different gemstones found in Sri Lanka. Crystals of tourmaline when heated exhibit electric polarity which in turn helps the ionic effect. Tourmaline is a crystal silicate mineral compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium.