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Molybdenum steel (an alloy of iron with a few percent of molybdenum) is used extensively for machine tool bits, because it is very hard and tough. Pure, or reasonably pure (90+%), molybdenum is used for very high temperature, high pressure chemical processing equipment, because molybdenum retains great strength at high temperatures, and is impervious to many forms of chemical attack.
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Small rectangle of foil 99.95%.
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: 1"
Purity: 99.95%
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Cylinder.
Purchased from Neil Lipson (Lipson@postoffice.att.net) after contact through eBay. No information on the source or use of this sample. This stuff is close to the density of lead, but much harder. It's a nice hunk.
Analysis by x-ray fluorescence spectroscopy at the Center for Microanalysis of Materials, University of Illinois (partially supported by the U.S. Department of Energy under grant DEFG02-91-ER45439) indicates that it is essentially pure molybdenum.
Source: Neil Lipson
Contributor: Theodore Gray
Acquired: 29 May, 2002
Price: $19
Size: 2"
Purity: 99.9%
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Nut and bolt, broken.
Purchased from Neil Lipson through eBay. This bolt was said to have been from a high-temperature pressure vessel of some sort. If you look at the broken surface in the high-resolution picture, you can clearly see that it's not like any steel, at least not like any I've ever seen. The melting point of molybdenum is a good 1000C higher than steel, and it's pretty strong stuff.
Analysis by x-ray fluorescence spectroscopy at the Center for Microanalysis of Materials, University of Illinois (partially supported by the U.S. Department of Energy under grant DEFG02-91-ER45439) indicates that this bolt is approximately 92% molybdenum with the remainder a mixture of cobalt and chromium.
So, in case you had any lingering doubts about whether someone would pay $13 for a broken 1/4-20 bolt on eBay, the answer is yes.
Source: Neil Lipson
Contributor: Theodore Gray
Acquired: 15 August, 2002
Price: $13
Size: 1.5"
Purity: 92%
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Tiny cylinder.
Ed bought half a dozen different tiny metal cylinders from David Franco, intending to make some kind of puzzle out of them (Ed's a puzzle person). But they turned out to be too irregular, so he donated them to the table.
Source: David Franco
Contributor: Ed Pegg Jr
Acquired: 19 August, 2002
Price: Donated
Size: 0.2"
Purity: 99.98%
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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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