Pearlescent

Pearlescent describes a surface, material, or finish that displays a pearly, iridescent luster similar to pearls. The effect is often called nacreous and results from light interacting with microstructures that are layered or plate-like, producing interference colors rather than a simple pigment color. In nature, pearlescent luster occurs in mollusk nacre (mother of pearl) and in some minerals with a nacre-like sheen. The term is also applied to natural gemstones or shells that reflect light with a soft, milky sheen.

In industry, pearlescent materials are engineered pigments and resins. Pearlescent pigments typically consist of mica platelets coated with metal oxides such as titanium dioxide or iron oxide, or with organic dyes. When incorporated into paints, plastics, cosmetics, or inks, they create shifting colors that depend on angle and illumination. The observed color can range from whites and pastels to rich iridescent tones.

Applications include automotive and architectural coatings, cosmetics like eyeshadows and nail polishes, and decorative plastics. Pearlescence is distinguished from metallic luster by its softer glow and from opalescence by less pronounced internal scattering; however, overlapping terms are used in some industries. The concept is also described as nacreous luster in mineralogical contexts.