The monetary unit of the state of Oman is the Omani rial. The currency unit of exchange is the baiza, equal to 1/1000 of the rial. In monetary circulation there are coins of 5, 10, 25, 50 and 100 baiza. Commemorative coins were minted in silver, copper, bronze, nickel-plated steel, bronze-plated steel, cupronickel, and copper-nickel alloy.