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tetragonal system
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Diagram showing the seven primitive crystal systems with labeled 3D shapes: isometric (cubic), tetragonal, orthorhombic, hexagonal, triclinic, monoclinic, and rhombohedral (trigonal), each with axis orientation and a brief description of their geometric properties. tetragonal crystal system Three illustrated crystals are shown to demonstrate different crystal classes and symmetries: a tall, prismatic monoclinic gypsum crystal; a pointed, double-ended tetragonal wulfenite crystal; and a cubic isometric halite crystal, each labeled with its crystal class and symmetry content.
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crystal systems
crystal systems The seven primitive crystal systems.

tetragonal system

crystallography
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tetragonal system, one of the structural categories to which crystalline solids can be assigned. Crystals in this system are referred to three mutually perpendicular axes, two of which are equal in length.

tetragonal crystal system
tetragonal crystal systemCrystals in a tetragonal system are characterized by three mutually perpendicular axes, two of which are equal in length.

If the atoms or atom groups in the solid are represented by points and the points are connected, the resulting lattice will consist of an orderly stacking of blocks, or unit cells. The tetragonal unit cell is distinguished by an axis of fourfold symmetry, about which a rotation of the cell through an angle of 90° brings the atoms into coincidence with their initial positions. The elements boron and tin can crystallize in tetragonal form, as can some minerals such as zircon.

This article was most recently revised and updated by John P. Rafferty.