Lustrous

Lustrous is an adjective used to describe a surface that reflects a significant portion of incident light, producing a bright, polished or shiny appearance. The term is common in fields such as mineralogy, geology, materials science, and product marketing, where it helps distinguish different surface finishes and optical qualities.

In mineralogy and geology, luster is a qualitative property that indicates how light interacts with a mineral’s surface. Luster is typically categorized as metallic or nonmetallic, with nonmetallic luster further described as vitreous (glassy), resinous, greasy, pearly, silky, or waxy. Adamantine luster denotes a very brilliant, diamond-like sheen. A mineral’s luster is judged on a fresh surface and can vary with lighting and observation.

Etymologically, lustrous derives from the noun luster, which in turn comes from Latin lux or related roots through Old French and English development, signaling brightness or shine.

In manufacturing and design, achieving a lustrous finish involves processes such as polishing, electroplating, or deposition that produce smooth, reflective surfaces with high specular reflectance. Lustrous finishes contrast with dull or matte surfaces, which scatter light more diffusely.

Common examples include metals like gold, silver, and polished steel, which are described as lustrous, as well as gemstones such as diamonds and pearls that exhibit strong sheen. Polished plastics, ceramics, and coatings can also be described as lustrous when they display a bright, reflective surface.

See also terms related to surface appearance, such as luster, gloss, and sheen.