1974 Half Dollar 10% Silver ?

[mtldealer]

I found this kennedy half the other night... I thought it was Silver but it didn't sound right. I tested it with XRF and it shows up as 10% Silver. Has anyone seen anything like this?

1974 Half Front.jpg (20.13 KiB) Viewed 708 times

[bman]

is it plated?

[Engineer]

It's probably silver that rubbed off other coins.

[hirbonzig]

Maybe the Philadelphia Mint was striking 10% silver coins for another country in 1974 that were half dollar sized and a mix-up happened.

[OtusLotus]

I don't really know how that machine works, but did you try testing different parts of the coin? The other side? washing the coin with a little soap and water?

Test it again on another 1974 half? weigh the coin to see if it weighs 11.5 grams...

If yes, yes, yes, yes, and no.. then I would send it to be graded!

[hobo finds]

This site has a 10% silver plated one mentioned. The guy Hobo is not me not sure if this is what you have.... http://www.cointalk.com/threads/1974p-9 ... ar.164678/

[mtldealer]

I added a picture of the weight... I guess someone could have silver plated it?

[LooseChange]

So I'm getting that it weighs less than a clad half at minting, so I can say the weight reduction could be accounted for with circulation wear, got it.
I can about 50% believe the plating story as that is a good bit of Silver to cover the surface, so that might come out to 10%.

**But what is the kicker for me, is how a clad coin can go from almost 92% Copper and 8% Nickel to 68% and 20% respectively. Was Nickel added, was Copper removed? This seems strange to me.

Lets say the clad composition stayed the same, minor wear, and there was no Silver on the XRF. (68/88)*11.26= 8.7 grams Copper and that would leave 2.56 grams Nickel. This from a coin that started off with 10.3 grams of Copper, and less than a gram of Nickel? Huh? If it is the same size as a half dollar, use your calipers, then there is really some explaining to do. Most of the Nickel was on the surface, why is there more now than what we started with? 20.5% of 11.26 grams is 2.3 grams, funky stuff.


My short answer: It's fake

My farfetched long answer: Copper was removed from the center and then replaced with Nickel from the surface. The surface Nickel that was removed and put into the center of the coin was replaced by the new surface Silver/Nickel alloy giving the outward appearance similar to that of a 40% half and it accounts for the increase in Nickel composition.
I really like the first theory though of another country coin being minted and this getting mixed in by "accident".

[creshka46]

The reader is probably only picking up the signature from the top of the coin. The clad coins are 91.6 copper and 8.3 nickel, but they are made by sandwiching 2/3 parts pure copper between 1/6 part CuNi (75:25 same as nickels) on either side. So the surface of the coin should read 75% copper, 25% nickel. Given the 10% allocated to silver, the percentages should be 67.5% and 22.5%.

This actually makes sense the more I think about it. If the reader is picking up only the surface of the coin, that explains the copper and nickel percentages as well as the extremely high silver percentage. So the silver only makes up 10% of the very top layer of the coin which is only a small fraction of the total coin weight.

So I'd say you have a silver plated coin there with probably less than 0.1g of silver.

Just MHO

[LooseChange]

Changed my mind.....I think creshka's answer makes much more sense than mine, especially since it answers the copper/nickel conundrum I had.

I'll up my "thinking its plated" to 90.3% sure (as that is the composition of the coin that is NOT silver)