By involving the iron from the original green clay (glauconite) in a series of chemical reactions providing multiple combinations of iron with the water's oxygen and hydrogen, the percolation of water is responsible for the current colors of the Provençal Colorado. Glauconite is first transformed into goethite (red) and kaolinite (white), then goethite locally subjected to subsequent percolation becomes hematite and limonite (yellow). The total leaching of iron oxides leaves only kaolinite and quartz (white), and the reprecipitation of iron on the surface leads to the formation of a dark red outer shell.