Iridescence is a phenomenon where surfaces appear to change color when viewed from different angles. This effect is often seen in nature, such as in the wings of butterflies, the feathers of peacocks, and the shells of certain mollusks. It occurs due to the interference of light waves reflecting off microscopic structures. The colors produced by iridescence are not due to pigments but rather the physical structure of the material. When light hits these surfaces, it is reflected and refracted in various ways, creating a spectrum of colors. This optical effect can also be found in man-made objects, like soap bubbles and CDs.