Tungsten
Tungsten is a hard metal similar in density to gold. Its hypoallergenic and hardness make it ideal for rings that will resist scratching, will not need finishing, and in rings that have a brushed finish.
Wedding bands crafted from Tungsten tend to have a lustrous dark hue as opposed to the white color of platinum. A ring made of tungsten and buffed to a bright, mirror like sheen will hold its shine for years and resist scratching, unlike many other metals such as gold and platinum with similar finishes.