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 Replies: 22 / Views: 5,009 |
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Valued Member
Australia
490 Posts |
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Pillar of the Community
Australia
4411 Posts |
Last week I saw with my own eyes a 20c coin in a PCGS slab that was 'copper'. The explanation of the error by PCGS was 'annodised' I think. That was one very expensive coin! That had a much deeper copper colour than this 50c. I have my doubts.
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Valued Member
 Australia
490 Posts |
I can see a copper 20c happening as there are copper coins of similar size and shape, but a dodecahedron copper blank of a similar size to a 50c? I have never heard of such a thing...
and usually "wrong planchet" errors are not exactly the same size/shape/weight...
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Valued Member
Australia
148 Posts |
Here are my copper coins.I know one is for real. I am pretty sure the other 3 are something else. TCH  |
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Pillar of the Community
Australia
1005 Posts |
Isn't "annodised" just a type of plating?
I thought it only applied to aluminium, but I could be wrong.
Without some type of verification, my money would be on it being copper plated.
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Pillar of the Community
Australia
1607 Posts |
Bit hard to fathom how a penny planchet could have gotten into a 1971 50 cent planchet bin,an exact weight in the listing would have been a must IMO.
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Pillar of the Community
Australia
877 Posts |
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Bedrock of the Community
Australia
21788 Posts |
In cetain specific storage circumstances, ALL copper nickel coins can discolour to a copper to a cpooer hue. That could be the reason for this one.
Another altenative is to copper plate it. That is quite easy to do.
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Pillar of the Community
1119 Posts |
red oxide coating of some sort?
and scratch ,arks on the obverse between the date and shoulder, testing to see if it took? they sure do appear to be fresh marks to me
Edited by erkle
09/10/2012 8:51 pm
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Bedrock of the Community
Australia
21788 Posts |
Accurate measurement of weight should confirm that the coin is composed of standard copper nickel.
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Pillar of the Community
Australia
1244 Posts |
Do you want a brown 50c, just stick it in a bag of 1&2c coins.
We had 5c and 10c coins turn brown this way.
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Valued Member
Australia
490 Posts |
I am awaiting the seller for an answer to my question on weight...  |
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Pillar of the Community
Australia
1295 Posts |
Quote:
Last week I saw with my own eyes a 20c coin in a PCGS slab that was 'copper'. The explanation of the error by PCGS was 'annodised' I think. That was one very expensive coin! That had a much deeper copper colour than this 50c. I have my doubts. That coin was most definitely not copper. That coin was what is known as an improperly annealed / sintered planchet. It basically happens when a planchet is covered in copper dust prior to being heat treated and the copper dust forms a coating on the coin. The planchet can get get covered in copper dust because the cleaning facilities might have been used to process 1 or 2c coins and then they were not cleaned properly. Alternatively a coin can become stuck in an annealing oven or pickling barrel and be contaminated with dust that way. |
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Pillar of the Community
Australia
515 Posts |
I also saw that coin in hand. It was slabbed by PCGS not as a 20c on a copper planchet, but as markn says an improperly annealed/sintered planchet which is an entirely different kettle of fish. A sintered planchet as markn says above is a light copper coating on the surface of the coin. On that particular con you could see a small area by the rim where the cupro-nickel was showing through.
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Valued Member
Australia
490 Posts |
thanks Markn and TPP - I was secretly hoping one of you might comment on this as your valuable insights here, as always, are enlightening. so, the $64 question (or maybe $6.40 question...) - what do you make of this 50c coin on ebay? similar improperly annealed/sintered planchet or not... or can't tell from the provided photos? |
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Pillar of the Community
Australia
1295 Posts |
Impossible to say. It could be an improperly annealed/sintered planchet, it could be someone's electroplating victim, it could have been left out in the sun for too long, or it could be stained with iodine or bromine or something similar. I'd say with confidence that the LEAST likely thing it could be would be struck with a copper planchet.
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Replies: 22 / Views: 5,009 |
Posted 09/10/2012 6:08 pm
