http://www.webelements.com has everything you could possibly want to know about elements such as Uranium.
The isotope [sup]238[/sup]U is about 99.3% of the uranium in nature.
[sup]238[/sup]U decays by Alpha emission to thorium. Alpha particles are very benign when not inside the body - they are stopped by a sheet of paper, or the layer of dead skin cells. It’s not a good idea to eat the thing, or sleep with it next to your body, but you will not get much of a dose from it.
If you put it in a ziplock bag you should stop most of the radiation - feel free to handle it whenever you want outside of the bag without risk, just don’t intentionally make a necklace out of it and wear it 24/7. Not that that would be particularly harmful, it’s just why add to your environmental alpha dose?
Everything you eat has some kind of radio isotopes in it - you’ll be fine.
Thanks guys - that’s what I thought in general, but I wanted to ask and make sure. It sure is neat having a chunk o’ Uranium around as a conversation piece.
Well, I agree it is safe unless inhaled or ingested. You may think that’s inpossible, but there are two common ways: if tiny grains rub off on your hands, and you later eat something without washing your hands, you’ll be ingesting uranium. If you shatter the piece, you may end up inhaling some uranium dust. So, to be on the safe side, I’d recommend washing your hands after handling it, and being careful not to break it.
Still, the concentration is pretty low, I doubt you’ll manage to inhale a dangerous amount even if you don’t take these precautions.
For some reason, much petrified wood from the Southwest acts as a sink for radioactive elements. I bet not 1 person in a million, (myself included) has followed these precautions, probably to their future eventual carcinogenic regret.
I grew up in western Colorado, where much uranium was mined in the 1950-70’s. (My dad was a geologist with the Atomic Energy Commision, predecessor of the Dept. of Energy.) After they mined and extracted the uranium from the ore, they had lots of tailings left over, which had low-level radioactivity from being next to uranium for eons.
Then someone got the bright idea, “Let’s offer these tailings for free as construction fill material.” So in the late 50’s and early 60’s, many building built in Grand Jct., CO, were built on these tailings, including schools, churches, and other public buildings. (My elementary school and my church were two such buildings.)
Then someone else realized that it might not be a good idea for public buildings to be resting on all these tailings. So there was a massive clean-up effort, where once a building was found to have these tailings, they were removed and neutral fill was put in in its place. (Removing the dirt under a building at the same time as putting new dirt in is quite difficult, as you might imagine.)
After cleaning up all the public buildings, they thought that private homes built in this era should be checked. My house was one such house. When the survey crew came out with a Geiger counter, my dad escorted them around, partly out of professional curiosity. Our house had normal background radiation, until they got to the corner by my bedroom. The count went up, then back down after they passed it. It wasn’t in the range of tailings, but it was something that warranted investigation. Then my dad got an idea. He went into my bedroom and found my mom’s old gem and mineral case, which I used as a bedstand. He looked through the drawers until he found what he was looking for: a uranium ore sample. He took it out to the crew, and they concurred that the sample is what was giving them the readings.
To make a long story short (too late), this meant that I’d slept for my first 14 years next to an emitting uranium ore sample. But as proof of my genetic health, I have a newborn baby girl who only has the requisite 10 toes and fingers. And she doesn’t glow in the dark. :D:D