A prismatic surface is a surface generated by all the lines that are parallel to a given line and intersect a broken line that is not in the same plane as the given line. The broken line is the directrix of the surface; the parallel lines are its generators (or elements). If the broken line is closed (i.e. a closed polygon), then the surface is a closed prismatic surface.
With regards to crystallography, a prismatic surface is a single face of a prismatic form, which is an open form consisting of three, four, or six identical faces related by a symmetry operator.
Famous quotes containing the words prismatic and/or surface:
“Then a small rainbow like a trellis gate,
A very small moon-made prismatic bow,
Stood closely over us through which to go.”
—Robert Frost (1874–1963)
“How easily it falls, how easily I let drift
On the surface of morning feathers of self-reproach:
How easily I disperse the scolding of snow.”
—Philip Larkin (1922–1986)