While glass that fluoresces brilliant green in UV light is perhaps the ideal yard sale discovery, snoopers may have unwittingly passed on a uranium glass treasure because it isn’t always easily identifiable in daylight. However, if you place that same glass under UV light, you’ll be rewarded with a spectacular dinner show. Uranium glass is, as the name implies, glass that has been cut with uranium, and the amount of uranium used can range from opaque to see-through. It can be green or clear in color, but it fluoresces brilliant green in a dark environment with UV light.
What is uranium glass, and how does it work? According to the Museum of Radiation and Radioactivity, swirling uranium into glassware originated in the 1830s as a way to impart color to glass. Uranium was added to glass for its green tint long before mankind realized its energy potential, much like other heavy metals have been employed to color it throughout its history.
Between 1958 and 1978, more than four million ornamental items were produced in the United States. There’s a lot of glistening glassware there. The majority of novelty glass has less than 2% uranium, although a few early 1900s pieces can contain up to one-quarter uranium. Uranium is a heavy metal and inherently radioactive element that has earned it a place in the atomic bomb recipe pages, which raises the question…
Is uranium glass a safe material? When it comes to radiation exposure danger, certain of the “hotter” uranium glass items might raise a person’s yearly exposure more than others. These include older pieces with a greater uranium concentration, which are more prone to leach into food or drink held in the glassware, exposing hands to larger doses of radiation, but still at a low level.
Natural uranium was used in some uranium glass, but after WWII, depleted uranium (DU) became more frequent. DU has the advantage of producing predominantly alpha radiation, which does not penetrate the skin and is hence not regarded a severe concern outside of the body. The goal of the “Systematic Radiological Assessment of Exemptions for Source and Byproduct Materials” was to look into the different radiation exposure pathways (leaching and skin contact) and doses from uranium glass.
They discovered that the persons most at danger from the items were those in charge of transporting them. They found that the highest anticipated dosage for a recreational uranium glass owner was just one to two percent of an American’s typical yearly radiation exposure. The International Gem Society, on the other hand, advises against cutting uranium glass without first following safety procedures.
How can I tell whether I’m looking at uranium glass? If you know what you’re looking for, which is glass the color of a wad of petroleum jelly, some types of uranium glass, such as vaseline glass, can be simple to recognize with the naked eye. However, in order to expose its radioactive potential, you may require an ultraviolet light and a dark environment. A bright green glow under ultraviolet light is a good indicator of uranium glass, and savvy collectors utilize black lights and Geiger counters to find the real thing. There are a few outliers that will not light despite the presence of uranium, but what’s the fun in that?