Les Jones

Science > Vaseline Glass Contains Uranium

I've seen many vaseline glass pieces in antique stores, typically arranged in a display case with a blacklight that makes them glow green. I just discovered that vaseline glass glows because it contains uranium oxide, and is also known as uranium glass.

At the end of the 19th century, it was discovered that uranium glass with certain additional minerals could be tempered at high temperature to partially crystallise, changing from its normal transparent yellow or yellow-green with increasing opacity to, ultimately, opaque white. This material, technically a glass-ceramic, inspired the name "vaseline glass" due to its similar appearance to petroleum jelly. Today, this term is the preferred term for all varieties of uranium glass, especially in the United States.

Uranium glass was originally used widely in the production of tableware and other decorative household items, but has long since fallen out of general use, and is most likely to be found as marbles for use as novelties or in science experiments. Most other objects made with this glass are considered antiques or retro-era collectibles, although there has been a minor revival in art glassware.

Regular uranium glass fluoresces bright green under ultraviolet light due to the uranium content. Certain other varieties will glow other colors. Uranium glass is scarcely radioactive, although a great enough quantity will register on a sufficiently sensitive geiger counter above background radiation. The radioactivity of the glass is widely considered to be negligible and not harmful.

Hat tip to Scribal Terror, which has lots of unusual links. More vaseline glass information at Southern Belle.

The red Fiestaware produced from 1936 to 1943 also contained uranium oxide. The manufacturer stopped using uranium oxide, not because of safety concerns, but because the U.S. government commandeered all uranium supplies for use with the Manhattan Project. Production resumed in 1959, but was discontinued again in 1969 due to safety concerns.