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 Replies: 23 / Views: 4,672 |
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Pillar of the Community
 Canada
9865 Posts |
Meanwhile, back to the OP's dilemma.
The non-magnetic coin in almost certainly a silver proof.
Do not remove it from its original packaging.
Any sign of tampering, however slight, will negate any error value the set has.
"Dipping" is not considered cleaning...
-from PCGS website
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New Member
 United States
34 Posts |
Well, I had it tested with an electron microscope today. The conclusion--an approximately 75/25 copper/nickel alloy. I have no idea where it may have come from, but it clearly was not the composition that it should have been. I guess a 75/25 C-N alloy isn't magnetic? Well, hopefully somebody will consider this "error" to be valuable. ;-)
56 percent nickel is required before the alloy shows ferro-magnetic properties at ordinary temperature. Thus, all makes much more sense, now (other than the origin of this non-standard proof planchet).
Edited by everycountrycoins
03/18/2016 03:15 am
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Pillar of the Community
Canada
9865 Posts |
Surprised that it is not silver.
Did you weigh it?
Did you get an accurate measurement of the diameter and thickness?
"Dipping" is not considered cleaning...
-from PCGS website
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Moderator
 Canada
10460 Posts |
Very cool... I occasionally see off-metal coins struck in mint sets, mostly from 1999-2000 sets...
"Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert OppenheimerContent of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_USMy eBay store
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Pillar of the Community
Canada
2845 Posts |
I think it's really cool as well! Your 25c is supposed to be pure nickel, no copper. I do happen to notice that RCM minted various cupronickel collector 25c in and around 2012 however they were larger at 35mm in diameter. But considering your analysis is equal to cupronickel, somehow it seems that a wrong planchet got added into your proof set. |
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New Member
United States
34 Posts |
Although the RCM didn't make any Copper-Nickel quarters of this size in 2012, the 2013 KM# 1547 was. I didn't weigh the quarter while it was out, but I'm pretty sure that it is a standard 23.9 mm. |
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Pillar of the Community
Canada
2845 Posts |
@ everycountrycoins that's very possibly the answer. Also because RCM mints coins for other countries, it's reasonable to conclude they maintained a supply of standard 23.88mm cupronickel planchets. In addition, thinking back, because 2012 was a year of change for RCM, the penny discontinued and the first year of offering two different types of proof sets it's also possible there was early experimentation regarding the specifications for each of the respective sets. Also, my understanding is that the COA sequence is not indicative of production order whatsoever. Rather, it's totally random. Most likely other 2012 sets also contain cupronickel quarters. Which brings me to my question, I'm just curious --- what was it that motivated you to check if the coinage in your set was magnetic or not? |
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New Member
United States
34 Posts |
It probably had something to do with my knowledge that there were two compositions of proof coins that year. I was looking at the coins, noticed that the composition was supposed to be nickel, saw the magnet near the mouse, and applied it to the casing outside the coins. It was a little obsessive compulsive, but sometimes those little actions that seem to have no rational basis can lead to discoveries.
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Replies: 23 / Views: 4,672 |
First Page
Posted 03/18/2016 03:07 am
