6mm Cobalt Flat Satin Finish w/ Koa Wood Inlay Band6mm Cobalt Flat Satin Finish Cobalt Offset w Koa Wood Inlay Size 10 (May be custom ordered in other sizes. Message us to place order.) Cobalt boasts a beautiful, Platinum like color which goes throughout the ring. Cobalt rings will not chip or crack, making it great for diamonds and custom work. Cobalt rings are malleable up to a half size. Cobalt is a light weight and hypoallergenic. In case of an emergency, cobalt rings can be removed with a diamond