Fire pit ring, a discussion.
You may also want to consider using a base of cast iron coated with heat resistant paint. You can even purchase a copper fire pit that already has a wire mesh screen attached. This can be tremendously useful in preventing fires that may result from flying sparks. The main building material of a copper fire pit is obviously copper. All things being equal, a copper fire pit provides all the same benefits of steel fire pits with the added benefit of being more durable.