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10 Oct 2018

That subtle uranium glow …

Written by Silvia Scopa
A Vaseline glass piece found at Pollok House
One of a set of Vaseline glass pieces stored in a box at Pollok House
Highly collectable Vaseline glassware achieves its rich shades of green and yellow from a small uranium content.

Vaseline glassware might be considered a little tacky for today’s taste but it was very much appreciated when introduced to the novelty-seeking market of the Victorian era. The origin of the nickname ‘Vaseline’ is linked to the resemblance of the shade, in some pieces, to Vaseline petroleum jelly, and it was coined at the peak of its popularity in the 1920s.

There’s evidence that uranium oxide, bright yellow when found in nature, was added to glass as a colourant in the early 19th century. The production of green and yellow uranium glass pieces continued throughout the Victorian period and was highly in demand during the Art Deco movement.

Another of the Vaseline glass pieces found at Pollok House
Another of the Vaseline glass pieces found at Pollok House

There’s a simple method to detect if something contains uranium and therefore is classified as radioactive: place the object under an ultraviolet light or measure its radioactivity with a Geiger counter. However, although this sounds fun and interesting, Project Reveal didn’t have any of these scientific tools at hand. Hence, we cannot be 100% certain of the uranium content in the objects you can see in the pictures, but we can still identify them as 19th-century Vaseline glass pieces. The uranium content gives these objects both their bright green colour and their distinctive glow; the radioactivity emitted by these items is minute and not harmful.

A Vaseline glass showing the distinctive bright green colour
A Vaseline glass showing the distinctive bright green colour

It’s still unclear as to who was the first person to experiment with uranium in the early 19th century, but it is clear that radioactivity would not have been on his/her mind as this phenomenon was only discovered in 1896. Georgian glassmakers had already used chemical elements to add colour to their work: cadmium (now known to be toxic) turned glass yellow, cobalt turned it blue, and the addition of manganese could create a range of violet shades. However, there was a gap as far as green was concerned. 

One of the first, and most famous, uranium glass makers was the Bohemian Josef Riedel, whose factory is still active today. He started production in the 1830s and launched two bright new colours into the glass market: Annagrün and Annagelb (green and yellow respectively). A renowned English producer of this innovative glassware was the Whitefriars factory in London, bought by James Powell in 1834. In the late 19th and early 20th centuries it produced high quality glass, which was exhibited at major international exhibitions and won lots of prizes.

Josef Riedel (1816–94)
Josef Riedel (1816–94)

The popularity of Vaseline glass eventually faded by the mid-20th century. There’s an interesting theory that links its fall in popularity with the widespread adoption of electric lighting – this took away the mysterious glow that these objects irradiated at sunset when placed on a windowsill in a dimly lit room.

Project Reveal is a Trust-wide collections digitisation project. It will result in an updated database with high-quality images and unique object numbers for every item in the National Trust for Scotland material culture collections. Six regionally based project teams, supported by experienced project managers, will work across all our properties with collections to complete the inventory in 24 months from July 2017 until July 2019.

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