The primary benefit of tungsten carbide rings is its scratch resistance. Having a hardness of 9 in Mohs scale, it is virtually scratch proof under normal daily wear. Diamond is the only gemstone that has a hardness of 10. Our tungsten carbide rings are all made using nickel as binder, so they do not contain any cobalt and will not cause any allergic reaction to your skin. All our tungsten rings are made true to size and have comfort fit design. Please note that tungsten carbide rings are not resizable due to the extreme hardness and high melting point. Our tungsten rings are all made from the highest quality tungsten carbide, we do not manufacture rings out of recycled materials. All our rings comes with lifetime warranty against craftsmanship defects. Tungsten carbide rings have a gunmetal color, which is a dark gray color compared to white gold or platinum rings.