Vitreous marble

Vitrolite was an opaque pigmented glass manufactured by Pilkington Brothers in the United Kingdom. It was made by The Vitrolite Company (1908–1935) and Libbey-Owens-Ford (1935–1947) in the United States.

The same structural pigmented glass was marketed as Sani Onyx (or Rox) by the Marietta Manufacturing Company from 1900 onward and as Carrara Glass by the Penn-American Plate Glass Company after 1906. The latter brand is named for the white or blue-grey Carrara marble, a structural veneer from Carrara, Tuscany, Italy for which the pigmented structural glass represented a lower-cost alternative.