Editing Category:Minerals (section)

===Luster===
Luster describes how a mineral appears to reflects light, and how brilliant or dull the mineral is. The terms used to describe luster are:

Metallic - Minerals with a metallic luster are opaque and reflective, like metal. The metallic elements, most sulfides, and some oxides belong in this category.

Submetallic - Describes a mineral that is opaque to nearly opaque and reflects well. Thin splinters or sections of submetallic minerals are translucent.

Vitreous - This luster accounts for roughly 70 percent of all minerals. Minerals with a vitreous luster have reflective properties similar to glass. Most of the silicates, carbonates, phosphates, sulfates, halides, and hydroxides have a vitreous luster.

Adamantine - Transparent to translucent minerals with a high refractive index yield an adamantine luster, meaning they display extraordinary brilliance and shine.

Resinous - This is the luster of many yellow, dark orange, or brown minerals with moderately high refractive indices - honey like, but not necessarily the same color.

Silky - A silky luster is the result of a mineral having a fine fibrous structure. Minerals with a silky luster have optical properties similar to silk cloth.

Pearly - Describes a luster similar to the inside of a mollusk shell or shirt button. Many micas have a pearly luster, and some minerals with a pearly luster have an iridescent hue. Some minerals may exhibit a pearly luster on cleaved crystal surfaces parallel and below the reflecting surface of a mineral.

Greasy - Luster of a mineral that appears as if it were coated with grease.

Pitchy - Minerals with a tar-like appearance have a pitchy luster. Minerals with a pitchy luster are usually radioactive and have gone through the process of metamiction.

Waxy - A waxy luster describes a mineral that appears as if it were coated with a layer wax.

Dull - This luster defines minerals with poor reflective qualities, much like unglazed porcelain. Most minerals with a dull luster have a rough or porous surface.


Every mineral has a characteristic luster, but some minerals may have a different luster on different specimens. There is no scientific method to determine luster. Often, determining the luster of a particular specimen is personal; to some it may appear as one type of luster, and to others as a different type.<ref> from Minerals.net:Luster</ref>