As the mythological phoenix bird senses death approaching, it builds a pyre, nestles down into the twigs and branches and bursts into flame. Consumed by the inferno, the phoenix does not die but arises whole from its own ashes to live again. And so it is with this strange green glass.
The term Uranium Glass is broadly applied to many different types of glass produced during the Great Depression (1929–1939). In that economic downturn, table wares were made from cheap pressed glass, affordable enough that it was even given away as premiums at gas stations. The most common colors were clear, amber, pink and light green. Colored glass is tinted by adding chemicals and minerals to a clear matrix; deep red is tinted with actual gold, deep blue is tinted with cobalt, and one of the chemical elements used to create that light green tint was uranium.
Yes, actual uranium, as in atomic bomb uranium, (although NOT that specific deadly isotope or in that extreme concentration!) Traces of uranium or other minerals were mixed in to make lovely clear pale green glass plates, teacups, bowls, candlesticks, vases, etc. It was not regarded as extra special and as pressed glass went out of fashion, it got stored away up in the attic. Because nobody used blacklights in their homes (the psychedelic ’60s still being a ways off), nobody was aware of the glass’s strange secret. But here it is: because of that barely radioactive element within, when hit with ultraviolet light, that glass glows BRIGHT, FLORESCENT GREEN.
And thus Uranium Glass rises from its obsolescence to live again for a new generation who hadn’t even been born when it was first made. People who might otherwise not be taken by an old-fashioned green glass measuring cup can see this glass in a way their great grandparents couldn’t, by ultraviolet light. Today serious collectors have dedicated display cabinets with mounted-in blacklights to show off their glowing horde. It looks AMAZING. And the glass’s weird special effect wasn’t even intentional! If you lived in the late 1930s, the only way you’d catch a glimpse of that glow was by looking through the right piece of glass backlit by the right ray of sunlight. The ultraviolet component of daylight (the wavelength that gives you a sunburn) can sometimes make the glass fluoresce slightly, so some early collectors searching outdoor flea markets would go in the late afternoon, when the low-slanting sun shows the effect better.
You can also buy blacklight flashlights off Amazon (people use them for night-hunting scorpions in the desert!) or use the penlights sold at office supply stores to test for counterfeit dollar bills. Just remember, not all green depression glass glows. And some only glows faintly while other pieces go nuclear. Some Jadeite (a semi-opaque pale green most often used to make utilitarian kitchen glass), and some Fenton Lime Green Satin, (an elegant, semi-opaque glass with a matte finish) and some Custard Glass (a semi-opaque, very pale yellow) also had uranium. Sometimes. And, uranium is not the only element in old glass that fluoresces. Magnesium, added to clarify glass, will sometimes glow if you are holding the right light. Because just as there is variation in the glow-power of the glass, there’s variation in the types of ultraviolet lights you can buy.
And what about safety? If your body has accumulated more radiation than average, i.e. you’re an airline pilot, X-ray technician, or cancer survivor you might think twice about displaying a gigantic stack of uranium glass right next to your bed, but for the average collector the risk is negligible. Although, Queen B has also sold vintage Geiger counters, if you’re extra curious.
Tuesday Treasures was started by our staff member, Jeanne Lusignan. Each week she will be featuring items that have been found at our estate sales. If you would like to submit a treasure for Jeanne to feature in a future installment of “Tuesday’s Treasures”, please follow the button below and send us an email! Please attach a few photos of your treasure in a beautiful setting as well as any details you have about your item such as manufacturer, use, age, region of origin. If you don’t know about the piece, that’s okay! We still might be able to research it for you! Don’t forget to tell us what makes this item such a treasure to you!