I came across some Uranium glass at a decent price the other day and thought it would be a neat novelty item. But like many consumers, I am weary of buying possibly radioactive materials. The glass is 800cpm (counts per minute) and I have no idea what that means. I’m assuming that they aren’t very dangerous, but I’d like to know for sure. In addition, I’m wondering if I would run in to trouble if I had some of it shipped to me. Any experts around?
Why do you want it? Personally, I wouldnt touch the stuff mate.
Don’t carry it around in your sporran
LOL!
Myglaren may have been joking, but I’m certain that the answer is the proper one. Almost 20 years have passed since my Nuclear Navy days, so the details about these things are a bit hazy. Nevertheless, the biggest danger with low-level radioactive material is from ingestion. Don’t let any food come in contact with it. In general, minimize your own contact with it. Radiation drops off rapidly with distance, so while it may be dangerous in your sporran, it will not harm anybody from your knicknack shelf.
This is a novelty item? How do you just come across uranium glass?
OK, Uranium oxides were used to obtain vivid color in many stoneware products, primarily made in the 1930’s. (Fiesta Ware, part of the “depression glass” phenomena.) Since it is natural uranium, the radiation is very low and it poses no external hazard. Since the uranium is incorporated into a glaze, in theory it will not contaminate food. These days most people don’t use them for food in case the glaze is damaged. However, there is no theory and actual evidence that would say they pose a real hazard since Uranium radiation is not much of an ingestion thread, only an inhalation concern. The only glaze materials for which I have seen real evidence of health effects are lead and cadmium.
Today, some people still make pottery with Uranium glazes, but usually not kitchen products.
I beg to differ.
Just to clarify: it isn’t the radiation that we swallow or breathe in, it is the radioactive substance. The actual radiation manifests itself as gamma rays, neutrons, electrons, helium nucleii and other assorted junk that is produced when a radionuclide decays.
Gamma rays go through just about anything – this is actually desirable since if it goes through you unmolested, it does nothing to your body. Neutrons are pretty good at passing through things since they have no charge. Electrons ('beta particles") are stopped by a sheet of paper, or a layer of clothing. Helium nucleii (“alpha particles”) are great huge bowling balls compared to all other particles and these plow through matter only a short distance before smashing into something and causing possible damage.
These “alpha” particles are the most destructive decay products because they are so massive (two protons and two neutrons) and because they have a +2 charge from the protons, causing them to interact quite readily with anything in their neighborhood. Fortunately, these are so huge that they are stopped by the layer of dead skin covering our bodies.
All types of particle radiation are more dangerous when there is no barrier between the substance and live cells. In particular, contamination in open skin wounds, in the lungs, and ingested all pose a higher threat than contamination on the surface of the skin.
Your garden variety U-238 undergoes alpha decay, so it is best to avoid any internal exposure.
From this site:
First check with eBay to make sure the price is right. There’s LOTS for sale. Keywords:
+uranium +cullet
+Radioactive +marbles
“uranium glass”
“depression glass”
“vaseline glass”
800 counts per minute isn’t very high, it’s a few times higher than background in a high-altitude city. If you fly in an airliner, the counts per minute all turing the trip is way higher. You can buy uranium mineral samples which have CPM up in the several tens of thousands. Still, I wouldn’t leave the glass in your pocket for weeks.
I can’t believe that no one’s mentioned that aside from any radiation dangers, uranium’s a toxic material. What many people suspect to be behind the Gulf War Syndrome is the gases given off by the burning of depleted uranium shells. (Depleted uranium isn’t terribly radioactive and the shells burn when whatever it is they’ve hit explodes.)
I dont think it’s toxicity would be much of a worry in some ornamental glass.
FYI, you can buy on EBay and in other place what people are claiming to be Trinitite. The validity of this is entirely up to the buyer, but surely some of it has to be real.
Uranium is more of a heavy metal poisoning concern than a radiation concern. There have been a lot of activist literature put out lately that attacks the U-238 in Depleted Uranium as dangerous due to the alpha decay. However, remember that the half life of U-238 is 4.5 BILLION years. It is almost non-radioactive. Ingestion is not much of a concern because most is excreted.
Here’s a reference that shows that the risk coefficients for ingested Uranium are two orders of magnitude less than inhaled Uranium.
http://www.oversight.state.id.us/ov_library/Contaminant_Fact_Sheets/Uranium_FactSheet_ANL.pdf
Different strokes for different folks. You may dine off of it if you wish and it most likely will do nothing. We certainly risk more getting in our car every morning than licking a Fiestaware plate.
Your point is taken. In the world of nuclear power, two interesting concepts are taught:[list=1][li]No level of radiation is totally harmless, and exposure should be avoided if practical.[/li][li]It’s all relative. We already get exposure from natural things, so don’t sweat the small stuff.[/li][/list=1]Clearly, the relative risk is very minimal; I’m standing by my statement, though, since it is so easy to avoid exposure that it costs virtually nothing.
I don’t like the idea of willfully ingesting an alpha emitter – your chart shows that the alpha from U-238 has 4.2MeV energy, quite capable of doing damage if it hits something.
Unit alert! You can’t make this comparison. In order to make a comparison between one sample and background, you need to specify (at least) how far away you are from the sample. Or if your count-meter completely encloses your sample, then you need to specify the size of the meter you’re using to measure the background.
Definitely correct if you want precision measurements. For rule-of-thumb, order-of-magnitude estimations, just appeal to the “standard:” a civil defense CDV-700. No doubt that’s where the 800CPM value came from. If mineral collectors talk about the counts per minute that a particular Torbernite sample gives out, that is CPM measured with a common civil defense geiger counter.
For the 800CPM quoted, placing your hunk of uranium glass against the end of the geiger counter probe is like taking the geiger counter to Denver or Mexico City (only go a bit higher than that for higher background count.)
On the other hand, if the radioactive object was far smaller than the end of the probe (e.g. a “hot” dust mote) then these vague estimations will be way off, and the danger of radiation burns would be greatly underestimated.
A story from a roommate Steve M. He visited some relatives in Poland during the cold war era. While he was stumbling to the john late at night in the darkness, he noticed several very dim green glowing objects scattered about the room. In the morning he discovered that they were beer bottles. His hosts said yes, beer bottle glass is “hot” because that’s how the Soviet Union gets rid of radioactive waste: vitrified in highly dilute form and sold as bottle glass. Which is more dangerous, holding such a beer bottle, or drinking the alcohol solution inside?
The only one of the Fiesta Ware colors that contained (depleted)uranium oxide was red. Production of red items ceased in 1943 and resumed in 1959; a non-radioactive red (“Mango Red”) was introduced in 1969 and ran through 1973.
Uranyl Glass (pronounced “urinal”, BTW) was made with uranium salt. It’s transparent yellow, and seems to glow. The glow is the result of fluorescence of the uranium salt, not to radioactivity. I’ve seen examples of uranyl glass vases at the Glass Museum at Corning, N.Y. Clearly, the uranium was used to get this striking effect (I believe the first use of uranyl glass in this was predates Becquerel’s discovery of radioactivity). AFAIK, the manufacture of such uranyl glass for decorative purposes ceased quite a while back, although they were still making uranyl glass optical filters for lab work until recently (and may still be doing so). My recollection is that the activity of such glass is pretty low, and that, since it’s encapsulated in the glass, you don’t have to worry about dust from it. I’d still keep it away from me, but I’m paranoid.
And just as a nitpick, Fiesta ware is ceramic, not glass. Depression glass is a different story altogether (although both date to the first half of the 20th century).
I still see Uranium glass in one particular place: little green beads surrounding the pins in large glass vacuum tubes. As I heard it, Uranium glass has the same expansion coefficient as copper, so it’s very easy to seal copper wires into your vacuum tube if it’s made of U-glass. For high-power devices you want to use copper because of it’s high thermal conductivity. Because of the expense, the next best thing to U-glass envelopes is to put little blobs of U-glass directly in contact with the copper pins, then seal those little blobs to the normal cheap borosilicate glass.