Iridescence is an optical effect where surfaces appear to change color as the angle of view changes or the angle illuminaton changes, or the intensity of illumination changes. Naturally iridescence can be seen in items such as oil mixed with water, insect wings and some sea shells.

Iridescence is often caused by multiple reflections from two or more semi-transparent layers in which a shift or interference of each reflection occurs.

Painters often produce iridescence by the use of mica, resin, and layers of gloss and varnish. Glass artists produce iridescence, when created fumed glass with the help of metal oxides.

Other words commonly used to describe iridescence are shine, sparkle, polished, reflective, luminous, fluorescent and glowing