Vitrolite: A Different Kind of glass

By Nicole Lind

Have you ever found a piece of opaque sea glass at the beach that looks like jade? If so, it might have been from a 1930s structural glass tile, known as vitrolite. So…how do you know you found a piece of vitrolite tile? A lot of beach-found vitrolite has two sides. One side is smooth and the other may have ridges. Because they were once wall or ceiling tiles, they are relatively chunky—from around 1/4 to 1 inch thick.

See beautiful images of vitrolite sea glass from beaches around the world and opaque sea glass from Seaham, England.

Here in Scotland we mainly find jade green, ivory yellow, and the occasional “secret” color, which looks black until you hold it against a strong light source. Try shining a light through this sea glass and you might be surprised to see an amazing glow of magenta or even blue. In Seaham, England, vitrolite is a common find on the beach. The colors range from common blue to tropical green (with amazing layers and looking a bit like emerald) all the way to the much-rarer shades of grey and peach. 

Vitrolite is not milk glass and is relatively easy to identify. To distinguish a piece of milk glass that came from a cold cream jar or an Edwardian toothpowder bottle from a piece of vitrolite, look for the ridges on one side and check the colors on the facing page to see if your beach find fits in. Of course, some beach-found vitrolite is worn down so much that the ridges are very faint or no longer visible. Sometimes the ivory color has an extra layer of white, so keep an eye out for that.

But what is Vitrolite?

Developed in the United States in 1900, pigmented structural glass was very popular for almost 50 years. Vitrolite is most commonly known as structural glass or vitreous marble. A combination of borax, cryolite, kaolinite, manganese, silica, feldspar, and fluorspar, the glass was fused together to create this very strong glass. The compressive strength of vitrolite is 40 percent higher than that of marble. Vitrolite was marketed as a sanitary, non-porous, and an economical substitute to marble.

Originally developed by the Marietta Manufacturing Company in Indianapolis, pigmented structural glass became so popular that it was made by several companies around the world. American manufacturers Marietta Manufacturing, Pittsburgh Plate Glass Company, and Penn-American Plate company and UK manufacturer Pilkington Brothers all made structural glass with names such as Carrara Glass, Sani Onyx, Sani Rox, Gladstone, Nuralite, Opalite, and Vitrolite. It wasn’t until 1916 when the Meyercord Carter company changed its name to The Vitrolite Company and began to manufacture a structural glass under the name “Vitrolite” that the term stuck, and most types of structural glass are now referred by the generic term “vitrolite.” 

Around 1906, the color palette was limited to ivory, white, jade, lavender, and black but by the 1930s production methods made it possible to add agate and marbled finished and over 30 different colors. But what was it used for? Initially invented to line refrigerators, the glass proved very popular and it wasn’t long before countertops, bathroom partitions, and storefront signs were made with this shiny new material. The germ-free quality of vitrolite meant that is was also used extensively in hospitals, meat markets and laboratories. Advertising slogans like “Porcelain like, that the mere stroke of a damp cloth keeps clean! A fire-glazed surface, impervious to liquid, moisture, and odor.”

Vitrolite tiles were made in large sheets of up to 108 inches by 40 inches with varying thicknesses of 1/4, 5/16, 7/16, 3/4, up to 1 inch, as well as entire baths and sinks. Vitrolite tiles could be backlit and sandblasted with company names and logos. It could even be cut into shapes and made into curved designs just like any other tile.

In 1912, the bathroom partitions and dados inside the Woolworth Building in New York were made with vitrolite and the popularity spiraled on from there. Updating storefronts and dowry insides of buildings was easy with this sleek material. The Art Deco and Art Moderne period epitomized vitrolite and the two are now virtually inseparable.

But why was it so popular in bathrooms and kitchens in residential homes? Pigmented structural glass does not craze or stain, is impervious to moisture, and can not absorb bacteria, parasites, or viruses—it is aseptic. The invention of this “magic” glass coincided with the discovery of germs and bacteria. New products were invented to kill germs and sterilize surfaces, and as people became aware of the existence of bacteria and the need to sanitize their homes.

With the color palette of vitrolite having reached more than 30 colors, you could match your bathroom and kitchen design with your wallpaper in the living room, and best of all—you simply needed to wipe the surface clean with very little effort. What’s not to love? Vitrolite was cheaper than marble, but looked very much like it and it came in lots of colorful options. But still… it was glass and despite not absorbing bacteria it could chip, just like any other type of glass.

Around 1947 production started to dwindle. New, cheaper ways to produce wall tiles were invented and after less than 50 years the industry fell out of love with vitrolite. Production more or less ceased after the Great Depression, and by the 1950s very little vitrolite was produced. The last two U.S. companies to make vitrolite were Libbey-Owens-Ford (formerly The Vitrolite Company—until the merger in 1935) and Pittsburgh Plate Glass, who both stopped production in the 1950s. Pilkington Brothers in the UK ceased production of vitrolite in the late 1960s. Only one German company was left to produce this once sought-after material until the end of the 20th century.

If you are lucky enough to live in a house from the 1930s with a vitrolite kitchen or bathroom think twice before removing it. In the USA efforts are being made to preserve historic buildings and their original materials, and some craftsmen specialize in the restoration of vitrolite and Carrara tiles. You can find amazing bathroom/bathtub surrounds and tiles on large auction sites like eBay. Even if you just want to dream of an Art Deco bathroom, check them out!

All photos by Nicole Lind.

Watch videos about all the colors of sea and beach glass

Learn more about sea and beach glass colors:

This article appeared in the Beachcombing Magazine January/February 2023 issue.