Adventist Youth Honors Answer Book/Nature/Rocks & Minerals/Luster

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 luster and pyrite is said to have a metallic luster.

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