Uranium glass, an older and more general term, is sometimes used as a synonym for Vaseline glass, but this can lead to confusion because some types of glass colored with uranium (e.g., custard glass and Burmese glass) are opaque whereas Vaseline glass is transparent.
The term “uranium glass” generally describes glass with uranium oxide, which glows under a black light. Other terms — Vaseline glass and Depression glass, for example — came later and apply more specifically to lighter yellow glass and glass made during the Great Depression, respectively.
Vaseline glass is sometimes used as a synonym for any uranium glass, especially in the United States, but this usage is frowned upon, since Vaseline-brand petroleum jelly was only yellow, not other colors.
How to Identify Uranium Glass. The easiest way to tell if uranium glass is real is to look at it under UV light. Real uranium glass will glow bright green under the light. The brightness of the colour will depend on the uranium content, but if glass glows under UV, it is unmistakably uranium glass.
Interestingly, new uranium glass is still being produced today, although very few manufacturers are left.
The uranium content in the glass is usually less than 2% by weight. While the uranium does emit low levels of radiation, it is generally considered safe to use for decorative purposes or as a collector's item.
Glass that contains manganese glows red, orange, or peach and even green under a UV black light. Selenium Glass - The process of de-colourisation and colourising glass was greatly used and Selenium was another mineral that was also used in order to achieve vibrant colours.
From circa 1943 until 1958, because of the events of World War II and the Cold War, U.S. officials did not allow the production of uranium glass since the government had banned uranium salts from commercial use. Only after uranium oxide was deregulated did the U.S. government allow uranium glass to be manufactured.
Shine a blacklight on the piece to see if it glows green.
Point a portable blacklight at the piece, and if it contains uranium, it will glow a bright green. Some pieces glow brighter than others, but as long as a piece glows, you know for sure that you've got a genuine piece of uranium glass.
Uranium glass will always fluoresce green. Basically it has to do with how the uranium atoms interact with with VU light and it's physically impossible for uranium to fluoresce any other color, so practically just remember that uranium always has a green glow. That being said there's two things to keep in mind.
Uranium glass is considered safe to wear and handle, according to the U.S. nuclear Regulatory Commission. In fact, it is considered to be safer than household electronics.
Fenton Art Glass Company stopped using uranium oxide in its glass in the 1970s due to concerns about the health risks associated with uranium. Fenton glass that contains uranium oxide is sometimes called "Vaseline glass" because it has a similar color to Vaseline.
What color of Depression Glass is rare? Pink and crystal (clear) are two of the rarest colors of Depression glass.
While the addition of gold enabled artists to create a beautiful shade of red that would remain vivid year after year, it also made red glass a valuable commodity. “Even today,” Geology.com says, “if you purchase a red sheet of glass it will cost significantly more than any other color.”
Uranium glass was produced regularly until just before WWII, when the US government halted production as uranium became highly regulated. This moratorium lasted until 1958, when uranium oxide was deregulated, and uranium glass has continued to be produced ever since (Collector's Weekly n.d.).
Perhaps the most reliable way to identify the presence of uranium in the glass is to expose it in the dark to a source of ultraviolet light (e.g., a black light). If the glass glows a rich green color, it contains uranium.
Look for a Fenton tag (used before 1970), look for the Fenton mark (“Fenton” in an oval), look for “F” in an oval, indicating another company's mold was used (1983+).
Uranium glass, or Vaseline glass, is a prized collector's item and is generally safe to handle.
However, since uranium is radioactive, you can also be exposed to its radiation if you are near it. Even if you are exposed to uranium, you might not be harmed. Whether you are harmed will depend on such factors as the dose (how much), the duration (how long), and how you happen to contact it.
To differentiate between manganese and uranium glass, it's essential to use the right UV light source. A 365nm UV light will reveal the subtle glow of manganese glass, while a 395nm UV light will showcase the vibrant fluorescence of uranium glass.
It's best to hold the blacklight about 1-3 inches away from the carpet or other surface you're examining. Look for that bright yellow color! Once you've found the urine stain, you can treat it with your favorite stain and odor removing product.
In the early 20th century, changes in manufacturing processes, as well as more pure batch materials, dictated different ways to decolorize glass, and the use of manganese oxide for this purpose dwindled.