Super Sparkling Machine Cut Cubic Zirconia, Brushed Finish, Comfort fit, 5mm width, Size 8 to 13, Heavy Duty Cobalt Construction, Hypoallergenic and Durable. Cobalt rings are a perfect alternative to Platinum rings. Not only are Cobalt Rings fraction of a cost of Platinum rings, but Cobalt is four times harder then Platinum which makes it durable and scratch resistant. Includes Designer Gift Box. Style SR10650