Crystal can refer to several different things:

Physical science

• In chemistry and mineralogy, a crystal is a form of matter wherein its molecules are regularly aggregated in a definite internal crystal structure, with the external form of a solid of symmetrically arranged plane faces.

• In physical chemistry, liquid crystal is a turbid liquid with some internal structure like an ordinary crystal, that exhibits double refraction.

Technology

• In electronics, a crystal (sometimes abbreviated XTAL) is a piece of quartz crystal used in a crystal oscillator to generate a stable frequency signal, as in a radio or a quartz watch. A different type of crystal in the past has been used as a diode in making a crystal radio receiver.

• Crystal glass is a form of glass with a high degree of transparency that usually consists of a high proportion of lead oxide.

Art

• A crystal is a piece of rock-crystal or the like used especially in magic art, such as crystal gazing.

Proper name

• Billy Crystal is an American comedian and actor.

• David Crystal is a British linguist and author.

Popular culture

• The Crystals was a highly successful American "girl group" of the 1960s, best known for songs like He's a Rebel and Uptown.

• In the fictional Marvel Comics universe, Crystal is a superhero who can manipulate the elements.

• Crystal is a slang term for methamphetamine, a synthetic stimulant drug which induces a strong feeling of euphoria and is highly addictive.

Computer software

• Crystal Reports is a commercial computer software product for creating reports about databases.

See also: Krystal