The Vesta is a polished tungsten ring with a black ceramic inlay. The tungsten and ceramic are a great pair as they are both incredibly durable and maintenance free.
The Metal that is used is a Nickel Binder that is higher in quality in comparison to cobalt. Cobalt is a inferior binding agent which may darken the color of the ring over time. Cobalt is most common in lower cost tungsten rings. This is due to the rings being mass produced in countries other than the United States.