Classical crystallography: An application of group theory

For centuries, many people have found beauty in the symmetry of crystals. All crystals possess some degree of symmetry, as is most apparent in crystals such as the snowflake. As crystals have the form of periodic repetition of some pattern or motif, the exterior symmetry of the physical crystal mimics the symmetry of the basic unit of the pattern. Thus analyzing symmetry can aid in understanding the atomic structure of a crystal.