Triclinic system
From Conservapedia
The triclinic crystal system has three axes, all of different length and none perpendicular to the others.
Crystals are usually flattened, with sharp edges and sharp, thin cross section; no right angles on faces or edges; all forms are pinacoids (open forms made up of two parallel faces).
Sources
- Chesterman, Charles W. The Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf: New York (1987), pp. 33-34