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Replies: 20 / Views: 3,551 |
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Valued Member
United States
122 Posts |
As some of you may remember, I inherited my Gradfathers coin collection & am still in the process of going through them. In his box full of Proof & Mint sets I find a 1964 Mint set wrapped in... wait for it... ALUMINUM FOIL! Why? Don't ask silly questions. But now they've all taken on the appearance of this pictured dime. So, now you know the easy way to get yours coins to change color.   
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Moderator
 United States
6563 Posts |
So the full set was wrapped in foil....I wonder why  Gots more pics?
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Valued Member
 United States
122 Posts |
If he was still alive, I would ask, I promise
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Pillar of the Community
United States
5318 Posts |
I'm guessing the toning wasn't due to the foil, but something environmental--perhaps BadThad has a better idea? 
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Valued Member
 United States
122 Posts |
Hmmmm, possibly, but the majority of the toning seemed to coincide with the parts of the coins that were touvhing the foil. Below is the Washington quarter. The Obverse was at the top touching the foil while the Reverse was not. You can see there doesn't seem to be much on the backside. BTW, the dime was wrapped separately so it had foil directly in contact with the front & back  
Edited by MrRick 01/07/2009 4:02 pm
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Pillar of the Community
United States
5318 Posts |
Yeah...I honestly don't know, maybe foil does something weird to silver? I'm curious to see what a chemist thinks.  I thought I'd tone some bulk silver someday by placing it in a sulphur vent near a volcano (as I'm a bit of a geology buff) Then I'd give away a bunch of "volcano toned" silver. 
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Valued Member
 United States
122 Posts |
LOL. Make SURE you post pics of those!
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Pillar of the Community
United States
1126 Posts |
Some People wrap coins in aluminum foil along with some packs of desiccant ( the little packs that they put in pill bottles to keep moisture out) to keep them from changing color. Trying to lock out any contaminates from the air. The foil can be molded and sealed to make it air tight and the desiccant to absorb any remaining moisture. that is in there while sealing. I personally do not do this but I have heard about it for years.
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Bedrock of the Community
United States
20753 Posts |
Probably a normal reaction of dissimilar metals touching each other. In metalurgy it is a known fact that any two different metals touching each other create an electrical charge during any change in temperature. It is really miniscue and seldom noticed by the average or normal measuring devises, but there non the less. It is the pricipal used in numerous industries for thermocouple wire systems of temperature measurements. An example is a small hole or indentation is made in an air duct or pipe, inserted with a threaded item and secured in place. A thermocouple head is screwed into that, two dissimilar metalic wires such as Cromel and Alumal are connected at that location and the other end to a sensitive gauge. Any change in temperature creats an electical charge and the gauge records that. Back to the coins in Aluminum. If these coins were placed in a location where temperatures varied repeatedly, such small electrical charges were created. With the possibility of moisture or other gasses in the air, these may have been forced electronically to create toning on the coins as noted. PS: Power station companies do studies of the ground prior to the construction of a power station for gradients and the possibility of high Aluminum contents. This is due to the usage of Copper Grounding wire systems. If there is large amounts of Aluminum in the soil, the Copper Ground wires will dissipate through electrical charges and combine with substances in the soil. A recent board plant company found this to be true in Pennsyvania and had to switch to Stainless Steel for grounding.
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Valued Member
 United States
122 Posts |
Wow Carl. Now THAT'S some info. Thanks
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Bedrock of the Community
United States
19943 Posts |
Carl is a smart man. I follow his lead: Two dissimilar metals in contact will create a micro-galvanic cell. The rate of electron flow between the metals will vary with temperature. Also, storage in just wrapped aluminum will not be air tight, so gases and moisture will move in and out throughout storage. As time passes, the coin will preferentially absorb compounds onto the surface, depending on the polarity of the gases and the micro-charge state of the coin. It's an interesting trick that could definately stimulate toning. 
Lincoln Cent Lover!VERDI-CARE™ INVENTOR https://verdi.care/
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Bedrock of the Community
United States
20753 Posts |
Most Nuclear reactors utilize the dissimilar metalic wire system for thermocouple metering. The wires are so sensitive that they will convey that signal for thousands of feet to the main control board. And this is from just two dissimilar metals touching each other at the thermocouple head. Naturally many different types of these wires are utilized pending the amount of temperature differentiations. The thermocouples on the air ducts of fossil power stations are of a much heavier material. Always rememeber this reaction if you place coins of different materials together.
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Pillar of the Community
United States
5318 Posts |
Quote: Always rememeber this reaction if you place coins of different materials together. --which explains that "special feeling" if you ever chew a bit of food w/aluminum foil, and it touches a dental filling. 
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Pillar of the Community
United States
1126 Posts |
I am wondering if I missed something I was under the impression that the coins were still in the mint holders " In his box full of Proof & Mint sets I find a 1964 Mint set wrapped in... wait for it... ALUMINUM FOIL!" Just wondering how two dissimilar metals can come into contact through plastic U.S. Mint holders? Just asking
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Valued Member
 United States
122 Posts |
They're not in the OGP anymore. The coins were raw, wrapped in aluminum foil with a scrap of paper marked 1964 Mint Set
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Pillar of the Community
United States
1126 Posts |
Now the coloring makes absolute sense Sorry guys looking at it from the wrong angle.
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Replies: 20 / Views: 3,551 |