Agate glass

Decorative opaque glass made by mixing different colors in order to imitate natural semi-precious stones such as chalcedony, jasper, and onyx as well as agate. Agate glass was produced in ancient Rome and from the late 15th century onward was produced in Venice and Germany. It is similar in appearance to pâte de verre which is produced by a different process. The term also refers to a type of art glass developed by Tiffany that resembles agate stone.