The same purpose is served by carrying amulets made from natural materials which have some unusual property which seems contrary to nature. A good example is mercury – a metal which has the unusual property of behaving like a fluid. Other examples include cat's eye, a semi-precious stone which resembles an animal's eye, and “fluid metal” (, "lek lai"), a metal-like substance believed to become malleable under the heat of a candle's flame. These items can be strung on cords and worn around various parts of the body, or inserted under the skin.