crystal (KRIHS-tul)
noun.

type of mineral that is clear and, when viewed under a microscope, has a repeating pattern of atoms and molecules.

crystal (KRIHS-tul)
noun.

type of glass in which a material (traditionally, lead oxide) is added to improve the glass' appearance. Also called lead crystal or crystal glass.

crystallize (KRIHS-tul-iz)
verb.

to become clear or definite.

ice crystal (IS KRIHS-tul)
noun.

solid ice arranged in precise molecular form.

liquid crystal (LIH-kwihd KRIHS-tul)
noun.

substances that have liquid qualities, but whose molecules are arranged like a crystal. Liquid crystals are not a liquid form of a solid crystal.

nanocrystal (NA-noh-krihs-tul)
noun. particle having at least one dimension smaller than 100 nanometres (nm) and composed of atoms in a crystalline arrangement. Semiconductor nanocrystals having dimensions smaller than 10nm are called quantum dots.
salt crystal (SAHLT KRIHS-tul)
noun.

single particle of salt, or sodium chloride.