This is a space for collectors to answer any questions about uranium glass that people may have.
I’d like to start with some questions I get pretty often (and that were recently asked by the admin of the instance, Wintermute):
How much Uranium is in the glass anyway? Should you even be holding that?
The actual uranium content in uranium glass is usually between trace amounts and 2% by weight, but you can find pieces that are up to 25% uranium by weight. (Source: ORAU Museum of Radiation and Radioactivity) Many of my pieces, when measured with a Geiger counter, are within what’s considered a low-risk range of radioactivity. Some people use their uranium glass, but I prefer to keep my handling of it to a minimum.
I think it only fluoresces like this under black light, right? Does it just look like normal glass in natural light?
UV light in general causes the glass to fluoresce. Black lights get you the best results, but some pieces fluoresce quite brightly under direct sunlight. Under natural light, most pieces are a transparent yellow-green.
Do they still make this stuff today, or is it all vintage?
Some companies make it today, but the majority you’ll find is vintage. The majority of my collection is from the 1910s-1930s, with a few pieces from the 1970s!
Where do you find it? If it’s mostly thrift stores and that kind of thing, do they usually know what it is or do they just think it’s regular glass?
Thrift stores, antique stores, auctions, eBay. Where I’m at, it’s mostly 50/50 as to whether the seller knows or not. That also influences the price – I’ve gotten pieces for under a dollar because someone just thought it was their grandma’s green glass.
Thanks for this thread! It answers some of the obvious questions I also had.
Given the variations in the uranium amounts in the glass, was some/a lot of it more of an incidental inclusion over an intentional mix in the glass creation? Not really sure how likely that may have once been as I’m not super familiar with glass creation (nor where uranium is typically found, come to think of it), but it kinda sounds like it may have been the case in some instances.
Hey there! Uranium oxide and pitchblende have both been used as a glass colorant since well before uranium was formally discovered – as far back as 79 CE! The pieces people commonly collect were intentionally colored with uranium oxide. I hope that’s clear!