Why is Ayers Rock Red?
The natural color of the rock which makes up Uluru is actually grey, it is only a thin skin which covers Uluru which is red, you can see this when you get up close to Uluru where the skin has flaked off, and in some of the caves around the base. The red color of Ayers Rock comes from rust, the rock contains high levels of iron, when iron is exposed to the air, it oxidizes, or rusts, so as the natural grey rock is exposed to the air, a thin layer of the rock starts to rust, this causes it to turn red. the longer a section of rock has been exposed to the air, the more is rusts and the deeper red it gets, this rusting process also make the rock substance more brittle. After some time the rock skin gets so brittle that it begins to fracture and flake, and eventually bits fall off. Exposing the grey rock underneath and the whole process starts again.
