Platinum occupies the other end of the value scale. Its price fluctuates, too, but at its best it is at least twice as much as gold and may be five or six times higher. Platinum, like the other noble metals, is very ductile and malleable, and it can be cast. It can also be forged and welded because it has a very high melting point compared to gold and silver. Usually about 10 percent iridium, a rather rare metal, is alloyed with platinum to contribute hardness. Although platinum is more difficult to work, because of its very high melting point, its great strength, good color, and absolute resistance to chemical attack make it ideal for use with expensive gems, such as antique diamond jewelry.