No, you are not seeing double. Rio Tinto plc, one of the world's largest mining operations (along with BHP Billiton and Vale), is the British half of a tandem of dual-listed companies. Rio Tinto plc's Australian counterpart is Rio Tinto Limited, which has its headquarters in Melbourne. Rio Tinto explores for a variety of commodities: bauxite, coal, copper, diamonds, gold, iron ore, minerals (borates and titanium dioxide), nickel, and potash. Iron ore makes up about 46% of the group's sales. The company also produces aluminum through its Rio Tinto Alcan unit.