Uranium Glass
What is Uranium Glass?Before people figured out how to make weapons with Uranium, it was a common glass colorant. Adding Uranium to glass it green and makes it fluoresce under UV light-- this is what is most appealing to collectors. Uranium in glass was so common that during the Great Depression so-called "Depression Glass" was often given away as promotional items with groceries or movie tickets. Once the government realized they could enrich Uranium to make bombs, glass production halted.
All these factors: the prior ubiquity, the UV glowing, and the fact it hasn't been mass manufactured in nearly a century makes it fun to collect. I bring a small UV flashlight with me whenever I go thrifting to check for Uranium glass. Most of the time, pieces are just a couple bucks if stores don't know what it is. Other times, stores will know exactly what they've got and they'll upcharge.
Uranium glass is not dangerous and it is safe to eat on. It is radioactive, but the radiation has been compared to the radiation of a ripe banana. Sometimes I'll drink out of my radioactive glassware, but mostly it's just for display.
Uranium glass can be somewhat tricky to identify. Most Uranium glass is green or green-ish yellow (green-ish yellow UG is often called Vaseline glass because its color is similar to petrolium jelly). There is no such thing as clear Uranium glass. If a clear glass glows under UV light, it's probably Manganese glass or something else. Another easy way to tell is the UV wavelengths:
| Glass Type | Regular Light | 365nm UV | 395nm UV |
| Uranium | Green/Green-ish Yellow* | Green Glow | Green Glow |
| Manganese | Clear | Faint Green Glow | Blue/No Glow |
| Lead | Clear | Blue | Blue |
| Selenium | Rose/Ruby | Pink Glow | Faint Pink |
| Cadmium | Yellow/Red | Yellow Glow | Faint Yellow |
*Most Uranium glass is translucent green under normal light, but it can also be opaque green (Jadite) or solid white (Custard). Both will glow under 365/395nm. The best way to reliably identify Uranium Glass is with a 395nm UV light since nothing else commonly glows green in that spectrum.
Once you know you've got Uranium glass, try to identify it! As your collection grows, you'll start noticing similar patterns and manufacturers. Sometimes you'll find a maker's mark somewhere on the bottom of pieces. This can help identifying what the pattern is since certain makers make certain patterns. For example, this is the mark for Federal Glass, a very common one:
Next, look at the pattern of the glass itself. Some patterns can be quite intricate and part of the fun of collecting is finding your favorite patterns in the wild. Are there floral motifs? Pleated patterns? Lace? There were tons of patterns made during the Great Depression, eventually you'll start to recognize them.
Here are some more favorites from my collection:
From 1930-1934 the Hocking Glass Co. made the Cameo AKA Ballerina/Dancer pattern. It's got a frilly pattern and features a dancer with streamers.
N.B. This piece is green under normal lighting, I just took a picture at an angle to showcase the pattern better.
Also by Hocking Glass Co., made from 1931-1935, the Princess pattern is one of the most desireable to collect. Most Princess pattern pieces (say that 5x fast) are square-ish, like this one.
This was my very first piece and holds a special place in my heart. It was made by Jeannette Glass Company somewhere between 1931-1935 and is known as the Foral or Poinsettia pattern. I recognized it as Uranium before I even had a UV light because the sunlight itself was making it glow slightly! A spicy piece for sure.
Next up from Indiana Glass is the Avocado AKA Sweet Pear pattern. Is it a pear? Is it an avocado? Yes!
Depression Elegant Glass - Index of Patterns