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Uranium ore (inside a Revigator).
Astatine, francium, actinium, and protactinium are irritating to element collectors. It's customary to say that all the elements up to uranium (92) are the "naturally occurring" elements, while those beyond 92 are man-made. Collecting all the man-made elements is of course impossible, since there's an open-ended number of them of increasingly short half-life. So people like to define a "complete" element collection as one containing all the elements up to uranium.
The problem is that astatine, francium, actinium, and protactinium are absolutely impossible to collect in any meaningful sense of the word. They are so fantastically radioactive and short-lived that if you had a visible quantity of any of them, you would be dead and then it would vanish before your body was cold.
Radon is a bit like this too, but not nearly as bad: You can have a glass vial with a macroscopic quantity in it. (Of course, it's an invisible gas, so you can't actually see it.) Technetium is theoretically collectable: One isotope has a very long half-life (but good luck actually getting any).
But astatine, francium, actinium, and protactinium are in a whole other league of non-collectability.
The customary solution is to take a chunk of uranium ore and explain that there's probably a few atoms of the elements somewhere in it at any given time. Uranium ore is better than refined, purified uranium, because the elements are generated several steps down in the highly complex decay chain of uranium. The ore has an equilibrium concentration of these daughter products that took many thousands of years to build up.
This is why my Revigator, which contains quite a bit of carnotite uranium ore, probably has more astatine, francium, actinium, and protactinium in it than my depleted uranium metal samples, even though they have far more uranium in them.
Source: eBay seller bettyboop@iolaks.com
Contributor: Theodore Gray
Acquired: 13 November, 2002
Price: $90
Size: 12"
Purity: <0.1%
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Sample from the Everest Element Set.
Up until the early 1990's a company in Russia sold a periodic table collection with element samples. At some point their American distributor sold off the remaining stock to a man who is now selling them on eBay. The samples (excepted gasses) weight about 0.25 grams each, and the whole set comes in a very nice wooden box with a printed periodic table in the lid.
Radioactive elements like this one are represented in this particular set by a non-radioactive dummy powder, which doesn't look anything like the real element. (In this case a sample of the pure element isn't really practical anyway.)
To learn more about the set you can visit my page about element collecting for a general description and information about how to buy one, or you can see photographs of all the samples from the set displayed on my website in a periodic table layout or with bigger pictures in numerical order.
Source: Rob Accurso
Contributor: Rob Accurso
Acquired: 7 February, 2003
Price: Donated
Size: 0.2"
Purity: 0%
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