Luster refers to the way light interacts with the surface of a material, giving it a shiny or dull appearance. It is an important property in various fields, especially in the study of minerals and gemstones. For example, a diamond has a brilliant luster that makes it highly desirable in jewelry, while a piece of chalk has a dull luster. In everyday life, luster can be seen in many objects, from the glossy finish of a car to the matte surface of a canvas. Understanding luster helps us appreciate the beauty and quality of materials, influencing our choices in art, design, and fashion.