Difference between revisions of "Hexagonal system"
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| − | The '''hexagonal''' | + | The '''hexagonal''' [[crystal system]] has four [[Axis|axes]] of [[symmetry]]: three, of equal length, lie in a plane at 120°; the fourth axis is longer or shorter and is at [[right angle]]s to the others. |
| − | [[Crystals]] are generally [[prismatic]] or [[columnar]], with | + | [[Crystals]] are generally [[prismatic]] or [[columnar]], with an [[hexagon]]al cross section; characteristic forms are six-sided [[prism]]s. The similar [[trigonal system]] (or rhombohedral) is often included within the hexagonal system. |
==Sources== | ==Sources== | ||
Revision as of 17:01, July 15, 2007
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
- Chesterman, Charles W. The Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf: New York (1987), pp. 33-34