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Aluminum is incredible stuff. If it wasn't so common, its combination of desirable properties, great strength, lightness, corrosion resistance, and easy workability, would make it seem incredibly useful. People would say, man, if only we could get more aluminum, we could make all kinds of things out of it! In fact, that's exactly what happened: When it was first isolated the only process for getting it was extremely difficult, and as a result it was rare and expensive. Napoleon had dinnerware made out the amazing new precious metal. But people knew it was common in many rocks and minerals, and before too long a quick, cheap process using electricity was discovered for refining large quantities inexpensively.
Today aluminum refining is one the largest users of electricity in the world. So much electricity is required that aluminum refining is done not near where the aluminum ore is, but near where the power is (for example near large hydroelectric plants that can supply cheap power).
Although aluminum is still more expensive than iron/steel, it is often used in place of cast iron because it is much easier to cast, and because the resulting pieces are much easier to lift. Although you might say that cast aluminum benches, lamp posts, etc, are "imitation", it's hard to think of a single way in which they are not superior to the iron originals. They are stronger (weight-for-weight anyway), they don't rust, they are much easier to install and move, you can paint them and expect the paint to last, and so on.
Rockets and large airplanes would basically be impossible without aluminum: No other material that is inexpensive enough to even consider using is light and strong enough to make a large jetliner work. (Some day carbon fiber composites and the like may take over this role, but at this point they are still way too expensive.)
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 4/0 electrical wires.
This was from heavy-gauge electrical wire left over from when we added the round house at the farm. It's been melted down and allowed to cool in the standard graphite crucible used for many metal samples. It came out very ugly, so I used a grinder, table top belt sander, and wire brush in the drill press to machine it into a cleaner cylinder with a pleasing texture on the surface. I got the wire from a building center in the mid 1990s.
Source: Hardware Store
Contributor: Theodore Gray
Acquired: 15 April, 2002
Price: $1/foot
Size: 1.25"
Purity: >95%
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Water drop blobs.
This globular stuff is what happens if you pour molten aluminum into a deep bucket of water. You can pour any kind of molten metal into water and each kind will give you different shapes. The shapes depend on how high you pour from, how much above its melting point the metal is, and how deep the water is. According to certain traditions, the shapes also depend on your fate, hence can be used to predict it (most traditions specify lead, but I don't see any reason why aluminum would be less likely to work for this purpose).
Any time you combine water with molten metal, there is a danger of the metal splattering. Generally speaking, if you pour metal into a reasonably full bucket of water, it sinks and cools too fast for any to splatter back at you (which is not to say it can't happen, so use a face shield). But if you pour (or even drip) water into a container of molten metal, it's a different story: That is quite likely to cause a steam explosion that throws liquid metal all over. So when you're pouring metal into water, the biggest danger is if any water happens to splash back into the bowl you're pouring out of. Pour away from you, so the bowl is between you and the metal, don't lean over it while you're pouring, and wear thick clothes and sturdy shoes along with a face shield or at least glasses. (I should talk: I made these lumps barefoot in shorts and no shirt. It's OK because I'm a trained professional idiot. And no matter what other precautions I don't take, I would never do this without glasses on. I can risk missing a few square inches of skin, but not missing an eye.)
These were made from the same wire as the sample above.
Source: Hardware Store
Contributor: Theodore Gray
Acquired: 15 April, 2002
Price: $1/foot
Size: 1.25"
Purity: >95%
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 Gem cut aluminum oxide (corundum).
These are real rubies and sapphires purchased from http://www.pehnec.com in April 2002. Real because they are chemically and crystallographically indistinguishable from naturally occurring gems (that would cost well into 5 figures). Present in the table because they are man-made (real, but synthetic).
Source: Pehnec Gems
Contributor: Theodore Gray
Acquired: 23 April, 2002
Price: $15/both
Size: 0.6"
Purity: 53%
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Artificial knee joint (practice version).
After starting to collect elements I researched industrial uses of pure elements in search of products I might be able to get as samples. For titanium and tantalum a promising source seemed to be artificial body parts, since these are the only two elements used for that purpose, because they are unreactive with human body fluids. I joked to my long suffering colleagues that all I needed to do was find the right body to dig up. I think they were worried.
And of course not two days later I found an eBay listing for a human tibia with attached artificial knee joint. (There is nothing you can't buy on eBay) The dealer seemed to be a legitimate outfit in Berkeley, California, and they indicated they thought it was probably titanium. I secretly hoped it was tantalum, which would have made it worth a serious amount of money.
I won the auction for $31, which seems like a very fair price for half of someone's leg. (This would, by the way, set the price for an arm and a leg at approximately $120, a real bargain.) But doubt remained as to the true identity of the metal. According to the seller, this item had been made by the manufacturer of the artificial knee for use in training surgeons in the use of that company's special drills and tools. I hope they learned well, because it's got several cuts on it where it looks like someone slipped....
Since it was never meant to be implanted into a living person, I was worried they might have saved some money by using a cheaper alloy. I was right to worry. 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 knee joint is made of.
Dr. Petrov's colleague Jim Mabon confirmed my fears with a quantitative analysis by x-ray fluorescence spectroscopy:
99.78% Aluminum
0.109% Iron
0.0062% Nickel
0.0053% Copper
0.0257% Zinc
In other words, common aluminum casting alloy. Interestingly, there was a 0.074% trace of titanium, which makes me think it was probably cast in the same mould, or maybe the aluminum was melted in the same crucible, as the titanium parts used on living people. There was not so much as the slightest detectable trace of tantalum. (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.)
Oh well, by then I'd become attached to my little bone, and it will have a place of honor under aluminum. After all, this was someone's leg, maybe someone's daddy's leg, and it deserves respect. (It is claimed to be a pre-1987 leg from India.)
Source: The Bone Room
Contributor: Theodore Gray
Acquired: 13 May, 2002
Price: $31
Size: 4"
Purity: 99.78%
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So-called "Titanium" racket.
"Racket" may be the right word for this sample, which used to be a racquetball racket prominently labeled as "TITANIUM". If it were titanium, it wouldn't have melted at about 700C in my crucible of truth.
It gets worse. It could have been one of many commonly used high-strength aluminum-titanium alloys, which contain a few percent of titanium: That would almost justify the use of the name "titanium" in the description. But 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 the following composition:
98.44% Aluminum
0.55% Manganese
0.53% Copper
0.24% Iron
0.16% Zinc
Where's the titanium you ask? It's not there, not even the tiniest trace.
Source: Chris Carlson
Contributor: Chris Carlson
Acquired: 10 June, 2002
Price: Donated
Size: 1.25"
Purity: >95%
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Fine powder, 99.999%.
Kindly donated by David Franco, who sent many elements after seeing the slashdot discussion, and this one after I sent him some Mathematica t-shirts.
Source: David Franco
Contributor: David Franco
Acquired: 11 June, 2002
Price: Donated
Size: 0.2"
Purity: 99.999%
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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: 99.99%
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Japanese coin.
I know I brought back a handful of these last time I was in Japan, but I can't find any of them. Fortunately Ed had some, and it's not like they're actually worth anything, which is why they are made of aluminum in the first place.
Source: Japan
Contributor: Ed Pegg Jr
Acquired: 6 September, 2002
Price: Donated
Size: 0.5"
Purity: >90%
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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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Ruby. (External Sample)
Ruby, the name given to the red form of corundum, is just simply aluminum oxide. It's very hard: Common sandpaper is made with aluminum oxide grit. Artificial rubies are dirt cheap because they are easy to make. Natural rubies are very expensive because they are hard to find.
This specimen is natural, but not clear "gem quality" ruby, which of course makes it much less expensive.
Location: John Gray's Collection
Photographed: 11 March, 2003
Size: 3"
Composition: Al2O3
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