CRYSTAL, n. [L. Gr., frost.]

1. In chemistry and mineralogy, an inorganic body, which, by the operation of affinity, has assumed the form of a regular solid, terminated by a certain number of plane and smooth surfaces.

2. A factitious body, cast in glass houses, called crystal glass; a species of glass, more perfect in its composition and manufacture, than common glass. The best kind is the Venice crystal. It is called also factitious crystal or paste.

3. A substance of any kind having the form of a crystal.

4. The glass of a watch-case.

Rock crystal, or mountain crystal, a general name for all the transparent crystals of quartz, particularly of limpid or colorless quartz.

Iceland crystal, a variety of calcarious spar, or crystalized carbonate of lime, brought from Iceland. It occurs in laminated masses, easily divisible into rhombs, and is remarkable for its double refraction.

CRYSTAL, a. Consisting of crystal, or like crystal; clear; transparent; lucid; pellucid.

By crystal streams that murmur thorough the meads.