caption: Slide 4 of 29: Bauxite rock is the world's principal source of aluminum, the second most commonly-used metal after iron. It looks like a reddish clay, and it's usually found near the ground's surface, meaning it can be mined easily. Bauxite is used to produce alumina (aluminum oxide), which is then electrolyzed to create aluminum metal. The US has relatively small reserves of bauxite ore, which is mined on a far greater scale in Australia, China, Brazil and Indonesia.