plural of quartz crystal

plural of Charcot-Leyden crystal

plural of space-time crystal

plural of thorn-apple crystal

(optics) A doubly refracting crystal in which the index of refraction for the extraordinary ray is greater than for the ordinary ray, and the former is refracted nearer to the axis than the latter, such as quartz and ice; as opposed to negative crystal: one in which this characteristic is reversed, such as Iceland spar or tourmaline.

(electronics) An early radio receiver, having no electrical power supply except the radio waves themselves; it used a crystal of lead or cadmium sulphide and a wire (the cat's whisker) touching the crystal's surface.

(chemistry) The water present in the crystals of the salts of certain metals; it is weakly bound by electrostatic forces and may normally be removed by heating.

Synonym of crystal set

(colloquial) The drug methamphetamine hydrochloride.

(chemistry, physics) A phase of matter similar to a liquid, in which the molecules are arranged regularly in one or two dimensions. / Material in that phase.