Hexagonal System

The hexagonal crystal system has four axes of symmetry: three, of equal length, lie in a plane at 120°; the fourth axis is longer or shorter and is at right angles to the others.

Crystals are generally prismatic or columnar, with an hexagonal cross section; characteristic forms are six-sided prisms. The similar trigonal system (or rhombohedral) is often included within the hexagonal system.

Sources[edit]

• Chesterman, Charles W. The Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf: New York (1987), pp. 33-34