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Tungsten is the foundational metal of my periodic table. The book Uncle Tungsten by Oliver Sacks got me started thinking about building a table. The first sample listed below (an eleven pound cylinder of tungsten) was one of the first samples I collected that really wowed me and other, and thus encouraged me to look for more elements in ernest. I like tungsten.
The commercial uses of tungsten fall into two categories; Those that exploit its high strength at high temperatures, and those that exploit its density. Tungsten is not as strong as any number of other metals at normal temperatures, but once you get into very high temperatures (yellow or white hot), the others start melting or dropping dramatically in strength, while tungsten keeps up a relatively high strength. This is the main reason it is used for incandescent light bulb filaments.
Tungsten is also by far the most dense element you can buy for less than precious metal prices. It's exactly the same density as gold, but something like a hundred or more times cheaper. Lead is cheaper still, but tungsten is almost twice as dense, and in applications where size counts, tungsten is used. This includes counterweights in aircraft control surfaces, for example.
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 Surplus 11 pound metal cylinder.
Purchased from Neil Lipson (Lipson@postoffice.att.net) after contact through eBay. Said to originate from a company closure.
This is by far the most tactile sample in the collection: People just can't put it down, because it's so darn heavy. I always point out that it's almost exactly the same density as gold, so holding this lump is as close as you're likely to come to the experience of holding about $50,000 (at $350/troy ounce) worth of gold.
I had a suspicion that it was probably not pure tungsten. Research on the internet indicated it was probably about 97% tungsten, 1% iron and 2% nickel. The iron and nickel are mixed with tungsten powder and the mixture heated under great pressure to fuse the iron-nickel alloy into a matrix around the tungsten particles.
Through the good graces of Inga Karliner of the University of Illinois physics department I was put in contact with Ivan Petrov of the U of I's materials research department, which just happens to be a national collaborative center for materials testing, which means they have a hallway with something like two dozen very fancy instruments for telling me what my tungsten cylinder is made of. (I was pleased that even at a national collaborative center for materials testing my tungsten cylinder was considered interesting and heavy.)
Petrov's colleague Jim Mabon confirmed my guess with a quantitative analysis by x-ray fluorescence spectroscopy;
96.32% tungsten
1.23% Iron
2.45% Nickel
(Per the terms of their service, I should mention that this analysis was carried out in the Center for Microanalysis of Materials, University of Illinois, which is partially supported by the U.S. Department of Energy under grant DEFG02-91-ER45439.)
Source: Neil Lipson
Contributor: Theodore Gray
Acquired: 29 May, 2002
Price: $315
Size: 3"
Purity: 96.3%
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 Bar of 99.99% tungsten.
Ivan Petrov (see above cylinder sample discussion) kindly donated a couple of very pure metal samples, including this lovely machined bar of "four nines" tungsten. It looks like powder metallurgy origin to me, but he didn't know for sure.
When NPR's Science Friday program asked to interview me about the Periodic Table Table, I decided to record "the sound of sintered tungsten", as mentioned in Uncle Tungsten. Oliver Sacks has actually listened to this recording and confirms that it's the kind of sound his uncle was talking about. (Wow, how authentic can you get!) Click the speaker icon to hear the sound of tapping this bar with a mallet.
Source: Ivan Petrov
Contributor: Ivan Petrov
Acquired: 6 June, 2002
Price: Donated
Size: 4"
Purity: 99.99%
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Welding electrode.
Rods of solid tungsten from 1/16 to 1/8 inch diameter and 3-7 inches long are used as electrodes in certain kinds of arc welding. Claudin Welding Supply kindly donated one when I went there looking for Hafnium.
Source: Claudin Welding Supply
Contributor: Claudin Welding Supply
Acquired: 24 July, 2002
Price: Donated
Size: 7"
Purity: >95%
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Fine wire.
This is really, really fine tungsten wire: 0.0025 inches diameter. It's quite strong, but what's really surprising as usual is how heavy the spool is. I need to figure out something to do with it, like hang a picture, because I've got 5000 feet of it.
Source: eBay seller 7890inky
Contributor: Theodore Gray
Acquired: 23 July, 2002
Price: $22
Size: 2.5"
Purity: >99%
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Tungsten Sparkplug.
Or at least, a sparkplug made by a company called Tungsten. I don't really know if there is any tungsten in any part of these sparkplugs, but I'll eventually test them and report what I find.
The most interesting thing about this sample is that not just one but two people would be willing to pay a minimum of $40 for a single rusty old spark plug (it takes two people to drive the price of an auction up). I'm not sure why I was willing to bid that high, and I certainly have no idea why the other idiot was, but isn't it wonderful that eBay exists to allow the exchange of a million people's junk into a million other people's treasure!
Here's an interesting article about different elements in spark plugs.
Source: eBay seller foos-15
Contributor: Theodore Gray
Acquired: 12 November, 2002
Price: $41
Size: 4"
Purity: 0%
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Tungsten/zirconium alloy screw plug.
Neil Lipson, the source of most of my tungsten and molybdenum, sent me this little plug in exchange for me analyzing what it's made of. He was hoping there might be iridium in it, but instead 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's a strange mixture of primarily tungsten (62%) and zirconium (30%), with the remainder being iron and nickel.
I looked around on the web and could find no references to tungsten-zirconium alloy, but that's no proof that such a thing isn't used in specialized applications. I would guess high temperature, corrosive environments, perhaps a chemical reaction chamber that operates at high pressures and temperatures.
Source: Neil Lipson
Contributor: Neil Lipson
Acquired: 18 December, 2002
Price: Donated
Size: 0.75"
Purity: 62%
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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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25mm APDS-T projectiles for 25mm Oerlikon KBB gun.
To quote from the website of the source (suppliers to the cannon-shooting hobby):High velocity discarding sabot projectiles for the 25mm Oerlikon KBB gun. They are black plastic with a black cap. Upon firing, the sabot breaks off into 3 segments, and the low drag core carries on at high velocity. Core is tungsten carbide, with a zirconium tip. Very impressive pyrotechnic display upon impact! White hot displaced metal arcs out in an umbrella pattern. In subsequent communications with the source, it appears that there are several variations that are not always easy to tell apart (it's hard to cut the plastic way to see what's inside, and of course that ruins the round). The one I got is tungsten metal (not tungsten carbide), and the tip is zinc-carbon alloy, basically a windshield that makes the shape more aerodynamic while permitting the tungsten core to have the optimal penetrating shape. (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).
Source: River Valley Ordnance
Contributor: Theodore Gray
Acquired: 6 March, 2003
Price: $15
Size: 3"
Purity: >90%
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Oliver Sacks' bar. (External Sample)
This is the bar of tungsten sent to Oliver Sacks by Roald Hoffman which triggered Sacks' memories of his uncle, which led to his writing Uncle Tungsten, the reading of which lead me to make the Periodic Table Table.
Sacks carries this bar with him everywhere, and when he came to visit the Periodic Table Table on November 12, 2002, I photographed it, so now it's an external sample in the table it created.
Now I just need to find and photograph whatever it was that triggered Roald Hoffman to send Sacks the bar in the first place. Eventually I should be able to trace this thing back to the big bang.
Location: Oliver Sacks' Wallet
Photographed: 12 November, 2002
Size: 3
Purity: >95%
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