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Tourney64
1000+ Penny Miser Member
USA
1035 Posts |
 Posted - 12/03/2007 : 19:49:19
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I was sorting using the 3 step method that Frugi described on an earlier post. 1. Sort for Zincs, 2 Sort non zincs for copper, 3 Sort remainder of coins for Zincs different setting. What is left in the rejects should be foreign coins and very old wheat coppers.
I did this with a Brink $25 box on Thursday and I got something strange in my rejects. A 1974 Philadelphia mint penny. I kept sorting it on the copper setting and it kept getting rejected. That was just too weird.
I decided to search the internet for 1974 pennies to see if there was anything unusual that happened to the coins that year. What I saw got me very excited. The price of copper in 1973 rose to a point that the mint was looking at alternative metals to mint pennies. They made 3 types of pennies all at the Philadelphia mint - aluminum, steel core coated with copper, and a 70% copper with 30% zinc dated for 1974. These coins were never officially released, but 12 aluminum ones got out, and 6 of the steel core covered copper ones are in the hands of 1 collector, and there is no record of anyone owning the 70% copper 30% zinc. The aluminum penny is actually estimated by some people to be worth between $100,000 and $1 million. The mint actually minted 2.5 million aluminum pennies and Congress didn't approve the metal change and they melted all those pennies. The ones that got out were handed to Congress as samples and all but 12 returned for melting. The 6 steel core ones, that the one person owns apparently fell out of bags at the steel mill where the coins were being melted.
I knew my coin wasn't an aluminum because of the weight and look, and it wasn't the steel core coated copper because it wasn't magnetic, and apparently the steel core shows on the edge of the penny. If anything it might be the 70% copper/30% zinc. Doing some math on the density of zinc and copper and the weight of the zinc pennies today and the pre 1982 copper pennies, I figured the weight should be 2.91 - 2.95 grams. I weighed my penny and it weighed 3.085 grams. Surprisingly most of the pre 1982 pennies I weighed on a super accurate scale that goes down 7 digits past the decimal for grams, were light. I can understand that over time the coins get worn and lose part of their weight. It doesn't appear that the penny is a 70% copper/30% zinc one.
At this point I have no idea why the coin is registering differently in the Ryedale Coin Sorter than any other coin from that year. I have looked thru my coppers for other 1974 Philadelphia mint and sort them with the unusual coin and the unusual coin sorts differently than the others. It's just strange that it's that year and that mint mark.
If anyone has some suggestions, let me know.
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Ardent Listener
Administrator
USA
4841 Posts |
Posted - 12/03/2007 : 19:59:57
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| My guess is that nickel could have been added to such coins. Perhaps by mistake. |
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Think positive. |
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Tourney64
1000+ Penny Miser Member
USA
1035 Posts |
Posted - 12/03/2007 : 20:58:01
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| Nickel could certainly cause the weight not to change. It would have been very expensive, if it was done on purpose. Nickel in 1974 - $1.75/lb, Zinc - .37/lb, Copper was .75/lb. |
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horgad
1000+ Penny Miser Member
USA
1641 Posts |
 Posted - 12/03/2007 : 21:18:52
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| Try putting an old wheat (with some tin in it) into your Ryedale and see if your 74 is a match or not. |
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fiatboy
Administrator
912 Posts |
Posted - 12/03/2007 : 22:11:29
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In the early '70's, people at the Mint were going bonkers---especially experimenting with different alloys. I wouldn't rule out anything. Seriously.
I can't wait till one of us finds some unknown penny alloy. Maybe you just did?
The weight of your coin is what's confusing me. Ought to be a normal penny, no?
Is it clean? Any superficial damage or anything unusual?
Keep us posted. I love a good mystery. |
"Bart, it's not about how many stocks you have, it's about how much copper wire you can get out of the building." --- Homer Simpson |
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Tourney64
1000+ Penny Miser Member
USA
1035 Posts |
Posted - 12/03/2007 : 22:41:24
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| It's clean and no damage. It looks 100% normal. |
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Ryedale
Administrator
USA
523 Posts |
Posted - 12/03/2007 : 23:19:32
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Tourney,
Thanks for the informative post. I too have found these strange 1974 pennies. When I first developed the machine in January of 2006, I think the first week I used it, I was finding many early 70's coins that were "rejected" when you are doing a copper keep pass, with a little extra sensitivity (about 1/3rd off full counterclockwise).
I have also experience some very strange behavior of some early wheats, and disturbing as it is I find it misses some on a high sensitivity zinc pass, and in order to get it to "reject", you have to turn the sensitiviy way up, to the point where it's rejecting nearly all zinc, How can this old wheat have the same electronic signature as a modern zinc. I dont know, it's one of the mysteries. I wish I knew somebody who had a HPLC analyzer and could run tests on these unique coins. Pehaps they alloyed them with lead or tin or some other metal. Who knows.
Thanks for the input, and set those oddballs aside, never know we may be on to one of the "mint secrets" here.
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Ryedale
GET YOUR DRI-SLIDE FROM IRONBRAID
http://www.ironbraid.com/driside.html
Used with permission from Ironbraid.
Quote
"The real art of conversation is not only to say the right thing at the right place, but to leave unsaid the wrong thing at the most tempting moment."
— Dorothy Neville-Rolfe |
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Tourney64
1000+ Penny Miser Member
USA
1035 Posts |
Posted - 12/04/2007 : 05:51:53
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| It is being rejected on the lowest sensitity, when comparing to copper. I'm going to try comparing it against other coins like Horgad said. Some very old wheats, different years of the Canadian pennies. What is a HPLC analyzer? I work at a large company that has all types of scientific equipment, so we might have something like that here. Would the HPLC destroy the coin? |
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cyberdan
Penny Collector Member
USA
289 Posts |
Posted - 12/04/2007 : 10:08:24
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quote:
Originally posted by Tourney64
What is a HPLC analyzer?
High performance liquid chromatograph (HPLC) detectors pass a beam of light through a column effluent as the fluid passes through a low-volume flow cell. Variations in light intensity are recorded and a chromatograph is generated. (did a quick google, I am not that smart )
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HoardCopperByTheTon
Administrator
USA
6807 Posts |
 Posted - 12/04/2007 : 10:26:46
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quote:
Originally posted by cyberdan
quote:
Originally posted by Tourney64
What is a HPLC analyzer?
High performance liquid chromatograph (HPLC) detectors pass a beam of light through a column effluent as the fluid passes through a low-volume flow cell. Variations in light intensity are recorded and a chromatograph is generated. (did a quick google, I am not that smart)
Damn.. another machine I don't have. Hello Santa? I been good.. |
If your percentages are low.. just sort more. If your percentages are high.. just sort more.
Now selling Copper pennies. 1.6x plus shipping. Limited amounts available. |
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snappy
Penny Collector Member
USA
301 Posts |
Posted - 12/04/2007 : 13:44:48
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| I have come across some (10-15) 2007/6's that rejected on zink and copper, I did not try them on an old wheat or magnet. I was not thinking I just tossed them in the zink and returned them already... makes a person wonder. it was not just a one time reject next time accept is was an always reject. |
Selling Ryedale sorted USA cents
1.5 each + shipping over 500fv 1.5 each +1/2 shipping
If you pick up 1.35 each
located MT/ND boarder.
after Ryedale sorting they are hand sorted to remove canadian then rechecked with Ryedale to insure all copper and count out $50 FV then placed in cloth bags and sealed with #1 copper wire. |
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Ryedale
Administrator
USA
523 Posts |
Posted - 12/04/2007 : 16:55:33
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Snappy,
Yes I have had problems with the 2007's also. Perhaps the zinc slug in the core is being "filled" a little with some other cheaper metal. Interesting stuff.
I said HPLC earlier, and I think it may be better to try this spark type device, They look expensive but I'll do some checking.
Perhaps HCBTT needs one of these at the day job
Website
You must be logged in to see this link.
Search ebay "spectrophotometer" quite a few hits
Description of Spectroscopy
You must be logged in to see this link. |
Ryedale
GET YOUR DRI-SLIDE FROM IRONBRAID
http://www.ironbraid.com/driside.html
Used with permission from Ironbraid.
Quote
"The real art of conversation is not only to say the right thing at the right place, but to leave unsaid the wrong thing at the most tempting moment."
— Dorothy Neville-Rolfe |
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HoardCopperByTheTon
Administrator
USA
6807 Posts |
Posted - 12/04/2007 : 19:27:34
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| We got some million dollar laser optical thing coming next year.. maybe we can use that. |
If your percentages are low.. just sort more. If your percentages are high.. just sort more.
Now selling Copper pennies. 1.6x plus shipping. Limited amounts available. |
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Tourney64
1000+ Penny Miser Member
USA
1035 Posts |
Posted - 12/04/2007 : 19:29:37
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| I'll check at our office for one of those spectrophotometers. We have several hundred HPLC's & HPGC's (Gas) at our office, but those appear to be only good for liquids. Do we know if the spectrophotometer will destroy/damage the coin? To me it seems like it would. |
Edited by - Tourney64 on 12/04/2007 19:34:50 |
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Ryedale
Administrator
USA
523 Posts |
Posted - 12/04/2007 : 20:08:40
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quote:
Originally posted by Tourney64
I'll check at our office for one of those spectrophotometers. We have several hundred HPLC's & HPGC's (Gas) at our office, but those appear to be only good for liquids. Do we know if the spectrophotometer will destroy/damage the coin? To me it seems like it would.
I would run some tests with whatever technician is available first, use "junk copper" coins first, and see what kind of damage it does. I dont think the test is extremely destructive, but I'm not sure. Thanks for looking into this. Andy |
Ryedale
GET YOUR DRI-SLIDE FROM IRONBRAID
http://www.ironbraid.com/driside.html
Used with permission from Ironbraid.
Quote
"The real art of conversation is not only to say the right thing at the right place, but to leave unsaid the wrong thing at the most tempting moment."
— Dorothy Neville-Rolfe |
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horgad
1000+ Penny Miser Member
USA
1641 Posts |
Posted - 12/05/2007 : 07:53:10
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I don't know what kind of detection system the coin counters at my credit union use, but I have noticed that ironically when the machine is being picky it rejects not only the grungiest coins but also the newest shiniest ones...everything in between it takes just fine...go figure.
Of course the stupid thing also thinks that about 1 in 5000 pennies is a dime and somehow even confuses them nickels every once in a while. Of course, I am not complaining about that. |
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Tourney64
1000+ Penny Miser Member
USA
1035 Posts |
Posted - 12/08/2007 : 17:00:27
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I just got another 1974 Philadelphia mint that was a reject on the lowest copper sensitivity against a 1980 Copper. I tried the sort against a 1911 and it accepted it as well as the other 1974 that was a reject from last weekend. I had several other 1974 Philadelphia mint coins and they rejected against the 1911. I'm not sure it's worth pursuing too much, but I'm going to do a post on the PCGS coin forum to see if any details can be had. What it tells me is the mint had 2 different metal contents in 1974 at the Philadelphia mint. They aren't supposed to do that unless Congress approves.
The question is - Would these coins, because they are different, have additional value as a result? |
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horgad
1000+ Penny Miser Member
USA
1641 Posts |
Posted - 12/10/2007 : 07:44:19
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It sounds like either the mint found a bag of blanks from the early 1900's and threw them in to be minted in 1974 or more likely it is a quality control problem at the place that makes the blanks. They got a little tin mixed in with the copper instead of zinc. There was not a chance that anybody would notice....until now.
I would think that if somebody could come up with an easy reliable way of telling the difference between the two varities that a market could be created for them, but I don't know how one goes about convincing the market that a new variety is worth collecting. Maybe if you gathered some more evidence you could write an article and submit it to some coin collecting magazines. That should cause a stir in the right circles...
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Frugi
Administrator
USA
627 Posts |
Posted - 12/10/2007 : 11:27:34
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| I HAVE A 1969 YELLOW BRASS CENT WITH A BROKEN DIE. I WAS TOLD IT IS A US CENT ON A FOREIGN PLANCHET, THE US MAKES ALOT OF OTHER COUNTRIES CURRENCY AND COINS. IT WEIGHS A LITTLE MORE THAN A BRONZE 1969 CENT, IT MIGHT BE WORTH SOME $$$. I FOUND IT HAND SORTING 5 YEARS AGO OR SO. |
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fiatboy
Administrator
912 Posts |
Posted - 12/26/2007 : 18:12:00
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Today I found one of these 1974 Mystery Pennies. I had the same results as Tourney64. I still have no clue what the alloy is.  |
"Bart, it's not about how many stocks you have, it's about how much copper wire you can get out of the building." --- Homer Simpson |
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Huge Find with Ryedale - ?
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