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Copper is a wonderful metal. As one of the very few elements that are colored in their pure form, copper has a natural edge over other metals in the attractiveness department. It's also stable in air and water (though it does tarnish some, it won't rust away the way iron does), highly malleable (which means you can bend and shape it easily), easy to cast, and reasonably inexpensive.
The definitive use of copper is of course for electrical wiring. Silver is actually a better electrical conductor than copper, but of course it's far more expensive and isn't used for wiring. Aluminum isn't as good a conductor as copper, but it's a lot cheaper and lighter, and for that reason aluminum is quite commonly used for wiring, especially for the thick wires used for the main service entrance for residential and commercial electrical supplies.
For a brief period of time aluminum wire was promoted for use inside houses for hooking up individual circuits: This turned out to be a disaster because it turned out that copper's malleability and oxidation resistance are just as important as its conductivity for electrical safety. The aluminum wires became fragile where they were bent to make connections, and they formed insulating oxide layers: Both points had increased electrical resistance which had the potential to overheat and start house fires.
So house wiring is back to all copper, and only copper.
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  3/0 electrical wire.
This wire was left over from when I rewired the main service entrance at the farm, and installed the backup generator in the early 1990s.
It's been melted down and left to cool in the standard graphite crucible used for several metal samples. The cylinders came out very clean and required only a power wire brushing to bring out the shine. Coated with a light coat of oil to retard tarnishing.
Copper is a good metal for casting: See zinc for more about metal casting.
Source: Hardware Store
Contributor: Theodore Gray
Acquired: 15 April, 2002
Price: $1.50/foot
Size: 1.25"
Purity: >99%
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Pre-1983 Pennies.
Before 1983, US pennies were made of solid copper. After the price of copper briefly went over a penny per penny, they reconsidered, and now pennies are copper plated zinc.
Source: America
Contributor: Theodore Gray
Acquired: 15 April, 2002
Price: $0.01/penny
Size: 0.5"
Purity: >90%
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Native Copper.
Found on a beach on one of the Apostle Islands in Lake Superior.
Source: Chris Carlson
Contributor: Lena Carlson
Acquired: 11 July, 2002
Price: Donated
Size: 0.6"
Purity: >90%
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Michigan Native Copper.
A Christmas present element: This ball came with the following tag:Michigan's Keweenaw Peninsula is the most important locality in the world for pure native copper. Mining began in 1845 and continued until 1968 and over 5 million tons of refined copper were recovered from Michigan's copper mines. In the early 1900's, it led the world in copper production and "Lake Copper" was the purity standard to which other refined copper was compared.
Long before the mining operations of the past century began in the Keweenaw, pre-historic peoples mined copper from the mineral-rich veins. It looks to me like this ball was melted down, probably from many small bits of native copper. Larger nuggets are much more valuable in their natural state, and are usually cut and polished, then sold for hundreds of dollars.
Source: John Gray
Contributor: John Gray
Acquired: 25 December, 2002
Price: Donated
Size: 1"
Purity: >90%
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Arizona Raspberry Copper Nodules/Nuggets.
Really strange looking nodules. The distinction between nodules and nuggets is that nodules are formed by precipitation or other chemical action while nuggets are formed by mechanical action in the solid state. At least, I think that's the distinction implied by this letter from the US Geological Survey, which offered an opinion on these things back in 1978 (click on the picture to get a readable version in a separate window):
The history of these rather strange nuggets is told by this letter, supplied by the eBay seller (who has more if you email him at coppernuggets@yahoo.com):
The seller supplied a copy of an analysis indicating them to be 94.8% copper, but not saying what the rest was, other than that it wasn't palladium, platinum, or rhodium. I confirmed the 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), getting a result of 94.9% copper, 5.1% iron. The iron explains the fact that they are slightly magnetic.
And they certainly are quite curious and pretty, whether the story is 100% true or not, which as you will see is an entirely open question as far as I'm concerned.
I cut one in half (actually I ground half of it away with a bench grinder), and this is what it looks like inside:
According to the USGS letter, the core is some mixture of copper oxides, but clearly the bulk of it is metallic copper. I made a QuickTime VR 3D image of the sliced version (warning, it's a high-resolution, 12MB file).
By way of fact-checking, I looked up the name on the USGS letter, and (probably on account of the unusual name), got lucky with the first email address I tried. The response was great:Yes, I am the same person although doing very different things now . I have my own business (www.specmin.com) and no longer work for the USGS.
I definitely do remember those nuggets.
We never saw anything like them again, to the best of my recollection.
In subsequent years, I have become a consultant to the mining industry and traveled extensively in South America to different mines and have not seen anything like them there either.
I have sent this out to a few of my copper industry friends and other contacts to see if they have
I will let you know if I get a response
Phoebe Hauff She's going to get some of the nuggets and show them around to her mining industry friends and of course I'll report anything that comes up.
Coincidentally I later got an email on an unrelated subject from another person, Joe Taggart, who currently works at the USGS. It turns out he knew Phoebe when she worked there. He didn't see the nodules when they had them in 1978, but based on the pictures on my website and Phoebe's letter, he said they looked like they might be pseudomorphs, clusters of cuprite crystals which were then converted into copper metal by the action of a reducing solution.
At that point I thought I knew the answer for sure: They were naturally occurring copper nodules! But that confidence lasted all of one day, because not long after the first email, I got another one from Joe saying, wait, wait, that can't be right. He'd thought about it some more and asked around with other experts in the field, and they said, no, those copper nodules are too dense to be pseudomorphs, they are a by-product of the electrowinning process of refining copper from copper ore. In fact, he said, a colleague has a similar nodule collected from just such an industrial operation.
Well, that settles it, right? Since the natural-origins theory has a number of issues, if they have a similar nodule that is known to be artificial, that would be pretty good evidence that mine are artificial too.
I was pretty well convinced that they were artificial at this point. But this new confidence was even shorter-lived. Just a couple of hours later he sent another email giving me permission to quote him on my website, but in this email he mentioned that the "similar" nodule they have has a flat side where the electrode was. Well, if my nodules had a flat side, or any visible point of attachment, I would never have had any doubt that they were electrolytic in nature! While the "natural origin" theory has problems, the "electrolytic" theory has problems too, like why the cuprite core, and how you can form a nodule electrolytically without any asymmetry or point of attachment.
It's not that I can't imagine any way this could be done, but all the ways I can think of seem unreasonable, like why would someone want to do that? It's possible that they are an accidental by-product of a refining process: I would not be terribly surprised. But I think it remains about equally likely that they are natural.
Personally, I really don't care one way or the other, I just want to know! They are very attractive and interesting objects regardless of whether they are natural or man-made.
In fact, despite not knowing their origin for sure, I've acquired a large quantity to use for trading. If you have any elements you think I'd like, maybe we can make a deal. If you want some of these nuggets and you don't have any elements, contact the source listed below because he's got more he'll sell you.
Source: eBay seller copper_nugget_man
Contributor: Theodore Gray
Acquired: 10 January, 2003
Price: Donated
Size: 0.75"
Purity: 95%
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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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Electrochemically grown crystal.
This beautiful man-made crystal was grown by electro-deposition from a salt solution. Presumably some kind of electrode was dipped in the solution and copper started growing on it under conditions that encouraged accretion at the ends rather than the sides of the dendrites. I believe these sorts of crystals are an unintended nuisance created during various electroplating operations, but they sure are pretty!
I have a very similar nickel crystal from the same seller.
Source: eBay seller conradboty@aol.com
Contributor: Theodore Gray
Acquired: 22 February, 2003
Price: $11.50
Size: 2"
Purity: >99%
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