For the file system called Lustre, see Lustre (file system)

Lustre (American English: luster) is a description of the way light interacts with the surface of a crystal, rock or mineral. For example, a diamond is said to have an adamantine lustre and pyrite is said to have a metallic lustre.

The word lustre traces its origins back to the Latin word lux, meaning "light", and generally implies radiance, gloss, or brilliance.

Other descriptive terms used for gems include vitreous, like glass; resinous, like amber; waxy, like jade; greasy, like soapstone; pearly; and silky.

The term is also used to describe other items with a particular sheen (for example, fabric, especially silk and satin, or metals).

See also

• hornblende for a description of lustrous ores.