Hi rbolo29,
Uranium used to be a major coloring agent for stained glass. When they had the reactor meltdown in the Ukraine at Chernobyl, they discovered that the molten uranium collected in the bottom, then melted through the concrete, spilling out in a colored glassy stalactite that solidified as soon as it had melted enough silicon in the concrete to lower the percentage of uranium.

When I was about 10, my father brought me some green ore that he said was uranium ore from the Appalachians in SC or NC. We kept it outside by the garage to avoid radon exposure. The Savannah River nuclear site was built by the AEC because SC had the largest deposit of uranium in the USA. However, they then discovered that there are numerous deposits that are higher grade and more economical to develop, even though they are smaller. I expect uranium ore to be colored and green is, in fact, the color that I expect from personal experience.

When I was a sophomore in college in SC, I worked in the physics lab building. We had to take our gamma ray spectrograms during the day, because each evening the temperature would drop and the pores in the clay soil that had swollen shut during the heat of the day would expand and open up. This would release the clouds of radon released from bedrock during the day. Depending on breezes and weather, the radon clouds rolling over the ground (radon is heavy) would sometimes reach the second or third story in the lab. The radon could mess up a spectrogram if you took it late at night.

This does not mean that radiation is not a significant public health hazard. It just means that there may be tens of thousands of deaths each year from radiation sources that are natural, not artificial. Forget about 'may be'. There are a lot of deaths from natural sources. The question is - how significant is the additional radiation from various artificial sources. I forget the percentage added by mining ore for nuclear power plants. It was small compared to the amount added by military bomb production. I seem to recall that it was closer to 1% than 10%. It has been a generation since I looked at the figures, but I seem to recall thinking that if we generated all the world's electricity from nuclear power and stopped making bombs, then we would cut the artificial radiation release into the environment significantly.

Lawrence