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Selenium used to be used in rectifiers, before the development of semiconductor-based diodes. They were big old things that didn't work very well (see picture below). These days selenium is in the news primarily when some place gets too much of it in the soil or water (either naturally or as a result of industrial dumping). People or animals eating plants grown in such soil can develop serious medical problems. On the other hand, selenium is also an essential nutrient with a minimum recommended level of 50mcg/day. It's all a question of quantity.
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Small button 99.999%.
Kindly donated by David Franco, who sent many elements after seeing the slashdot discussion.
Source: David Franco
Contributor: David Franco
Acquired: 17 May, 2002
Price: Donated
Size: 0.1"
Purity: 99.999%
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Rectifier.
Before the invention of silicon and germanium rectifiers, these were state of the art. Despite being called "miniature" rectifiers, they are huge by current standards!
Source: Charles Cowie
Contributor: Charles Cowie
Acquired: 9 September, 2002
Price: Donated
Size: 2.5"
Purity: >90%
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Hunks.
These are bigger hunks of selenium from Canada, about 20 grams each. They are nondescript as elements, but do illustrate what a wonderful place eBay is to deal with. The first one failed to arrive after a while, so I emailed the seller asking if it had been sent. He assured me it had, but offered to send another if it didn't arrive soon. It didn't, and he did. Naturally not long after that, the first one arrived in a torn, dirty envelope postmarked almost a month before that looked like it had been opened, but still contained its lump. The replacement arrived the next day. People on eBay are just the nicest people you'd ever want to meet.
Source: eBay seller kingendymion
Contributor: Theodore Gray
Acquired: 27 September, 2002
Price: $26
Size: 1.5"
Purity: >99%
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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.
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: >99%
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