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 Replies: 14 / Views: 2,888 |
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Pillar of the Community
3352 Posts |
Iridescent toning, or just some sort of plague? ... I'm not quite sure why these copper coins are showing iridescent colors/hues (could previous cleaning have caused this to happen?) ... or could it be from the Whitman Album that the coins have been housed-in during the past 40 years? ... or is this merely common-place for pennies as they "grow older"? Oh => and I do apologize for the rookie coin-photography (baby-steps to Life Magazine)   |
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Pillar of the Community
Canada
1610 Posts |
I don't know. I have one like that, it's an 1808 10 cash coin in great shape and it's luster has like a red-purple toning, kinda weird.
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Bedrock of the Community
United States
20753 Posts |
So what did you expect putting a Canadian coin in a USA Album?  In other words I too have no idea? |
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Pillar of the Community
Australia
7096 Posts |
I hope that these are 2 different coins because George 6th didn't appear on coinage until 1938.
The toning could be due to the mint lustre reacting to something.
They look like pretty high grade coins
i have a few Aussie copper coins that have similar toning
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Pillar of the Community
 3352 Posts |
Thanks for responding, gang ... trout1105 => if I had a 1932 penny with George 6th on the otherside, the iridescent toning would be lower on my list of concerns! (yes, the photos above are showing two different coins) ... There are actually a few more coppers in the album, that are showing the same type of toning ... that is why I was curious whether it was perhaps a "bad" thing?  |
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Rest in Peace
United States
9104 Posts |
If you don't find it desirable, it's "bad".
The most beautiful rose in a potato field is still a weed.
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Bedrock of the Community
United States
12437 Posts |
Quote:
could previous cleaning have caused this to happen? Yes, that is an indication of a previous cleaning that has begun to retone. |
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Pillar of the Community
3352 Posts |
biokemist6 => so if I merely leave it alone, will the coin eventually "tone-over" and lose this iridescent quality and one day look like a "normal coin"? (for lack of a better word)  thanks for responding Edited by stevex6
11/28/2011 11:58 am
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Valued Member
United States
193 Posts |
I'd like to chime in on this topic. I have found some modern clad cons that show that kind of toning. Is it possible for clad coins to get that iredescent toning? or is there anothre reason.
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Rest in Peace
United States
9104 Posts |
Clad is still 75% copper on the outside.
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Valued Member
United States
193 Posts |
Biggfredd; I have a couple of clad dimes with toning on them.
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Rest in Peace
United States
9104 Posts |
copper tones, just like cents
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Bedrock of the Community
Australia
21786 Posts |
Sorry for the double posting, the first deleted
Edited by sel_69l
12/03/2011 11:04 pm
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Bedrock of the Community
Australia
21786 Posts |
I would just like to put a different angle on why the purple tone is present.
During WW2 the copper used to make bronze alloy for Australian coins was less well refined. The copper had trace amounts of gold in it, which was not worth removing because of the extra work involved, when everybody was flat out to assist in the war effort.
As some of us may know, finely divided silver is black in colour, which is why it was used in photography.
Gold, when finely divided, is purple.
Some Australian bronze coins of WW2 display the same purple tone, (from gold leaching the the surface during rolling?) and I suspect that the gold toning in the case of the Cent pictured here may be for the same reason.
Perhaps speculation, but worthy of consideration.
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Rest in Peace
United States
9104 Posts |
I would think that modern processing would more aggressively remove gold.
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Replies: 14 / Views: 2,888 |
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Posted 11/19/2011 4:09 pm
