Crystal glass refers to a type of glassware that is made from clear, colorless and highly transparent material. It is often used for decorative purposes due to its beauty and clarity. The term "crystal" can also refer to leaded glass which contains small amounts of lead oxide to increase the density and improve the optical properties of the glass. Crystal glassware is known for its high quality, durability, and elegance, making it a popular choice for various applications such as drinking vessels, decorative items, and tableware.