Minerals are classified on the basis of their chemical composition, which is expressed in their physical properties. This module, the second in a series on minerals, describes the physical properties that are commonly used to identify minerals. These include color, crystal form, hardness, density, luster, and cleavage.
Properties that help geologists identify a mineral in a rock are: color, hardness, luster, crystal forms, density, and cleavage.
Crystal form, cleavage, and hardness are determined primarily by the crystal structure at the atomic level.
Color and density are determined primarily by the chemical composition.
Minerals are classified on the basis of their chemical composition.