The Seven Colored Earths of Chamarel is the main tourist attraction of Mauritius and still mystifies geologists. The natural formation shows seven colors of variation from ocher to brown, red, purple, green and yellow.
All the soluble elements such as silicon dioxide have been washed out and have left reddish-black iron and aluminum oxides creating shades of purple and blue. If you mix the colors, they will naturally separate out into their respective colors. A fence protects this area and tourists are not allowed to walk on it. They can purchase vials of these sands in the gift shop.