The isometric crystal system has a unit cell in the shape of a cube. It is one of the most common and simplest shapes found in crystals. The crystallographic axes used in this system are of equal length and are mutually perpendicular, occurring at right angles to one another.

All crystals of the isometric system possess four 3-fold axes of symmetry, each of which proceeds diagonally from corner to corner through the centre of the cubic unit cell. It is the most symmetrical system possible in three dimensional space.

The isometric crystal system has the following forms:

  • Cube
  • Octahedraon
  • Dodecahedron
  • Trapezohedron

Diagrams from What is Crystallography and Rockhounds