The mineral property that describes the way a mineral reflects light is known as luster. Luster can be defined as the quality or appearance of light reflected from the surface of a mineral.
Minerals can exhibit a variety of luster types, categorized into two main groups: metallic and non-metallic. Metallic luster, as the name suggests, gives a shiny appearance similar to that of polished metal. On the other hand, non-metallic luster can display a range of appearances, such as glassy, pearly, silky, or dull.
Understanding luster is important for mineral identification, as it is one of the first visual characteristics observed when examining a mineral specimen. For example, a mineral with a glassy luster like quartz can easily be distinguished from one with a pearly luster like talc. Overall, luster provides valuable information about the physical properties of minerals and aids in their classification.