Editors at Wikipedia, the world's online encyclopaedia, have decided not to have an entry for Vitrolite, the structural pigmented glass known throughout the world, and instead use the term 'Vitreous Marble', which is a description used in some 1930s advertising for the Vitrolite alternative, Sani-Onyx.
 
Wikipedia states:
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.
 
The term vitreous marble was used by Marietta Manufacturing as a generic identifier[2] for pigmented structural glass, although the genericised trademarks are in common use.
 
In their discussions about terminology, the editors wrote: Vitrolite, Sani Onyx and Carrara Glass were trade names for pigmented structural glass from different former manufacturers. 'All were glass replacements for architectural marble, common in the art deco and streamline moderne construction of the 1930's through 1950s. To list this under one manufacturer's trade name only violates neutrality; it should be under the generic name and all of the various genericized trademarks redirected there. There doesn't seem reason to favor one brand over another unless one has become both dominant and genericized, which is not in evidence.
 
The earliest reference to Vitrolite in Great Britain seems to be for a horticultural paint produced in Great Britain around 1903 by Walter Carson & Co.
 
By 1907 the Meyercord Co in the USA had named a range of cylidnrical backlit illustrated glass advertising signs 'Vitrolite'.
 
Meyercord wrote: This sign, which the Meyercord Co. have named the 'Vitrolite Sign' will without doubt make an epoch in the history of sign development of the world. The Meyercord Co. have the credit of putting out the first permanent colored vitrified glass.
 
Later in 1907 the Vitrolite Company was formed in Vienna, West Virginia, under the direction of glass technologist Daniel Sharp Beebe, and began producing pigmented structural glass, as a substitute for marble in dairies where the more hygienic glass surface of Vitrolite harboured fewer germs and bacteria.
 
Vitrolite began selling its products through outlets worldwide, and apparently began licensing its technology, one of the first of which was Pilkington Brothers of St Helens who was manufacturing Vitrolite in 'collaboration with the British Vitrolite Company Ltd' of London.
In 1931 the American Glass Review wrote: 'The British Vitrolite Co., Ltd., has been chartered as a private company in England with a capital of £15,000 to acquire the undertaking of the Vitrolite Construction Co.'
 
In its introduction to Vitrolite Specification, published in 1938, Pilkington Brothers wrote: Vitrolite is a Rolled Opal Glass, ranging from semi-opacity to complete opacity. One surface is usually impressed with a pattern of narrow parallel ribs which provide a key for the mastic or other material with which the glass is fixed. The glass has a hard, brilliant, fire-finished surface.
 
'Vitreous marble' does not seem an accurate generic description of Vitrolite, but is more an advertising slogan. 'Rolled opal glass' would seem more fitting, but it would seem that most people prefer Vitrolite.