This is an aztec-styled chess set. It was purchased in Mexico several years ago, and given to me. I believe the material is onyx. I was told by the people who purchased the set that it is hand carved stone. The white set is bare stone, displaying natural veining in the body of the stone. The green set has been dyed / painted green over the same stone. The kings are 6+ inches tall. The one flaw is that the white king was dropped several years ago, and a piece of his crown broke off. It has been securely glued back on.
The pieces have a lovely design. The faces of the kings, queens, bishops, and pawns look like aztec monuments. The price is currently less than $0.50 per piece. Paperweights made of onyx cost more than that!