Specialty Glass
Glass is an amorphous (non-crystalline) solid material that exhibits a glass transition, which is the reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle state into a molten or rubber-like state. Glasses are typically brittle and can be optically transparent. The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% Silicon dioxide (SiO2) plus sodium oxide (Na2O) from soda ash, lime (CaO), and several minor additives. Often, the term glass is used in a restricted sense to refer to this specific use.