Copper / Nickel Alloy Question - Copper Dime
No I did not find it in a parking lot but did find it quite a few years ago in a CoinStar. This is a metallurgical type question as to how this occurred. The piece in question is a 1990 something dime that is missing the cupro-nickel jacket. I am guessing someone dipped this dime in something that removed the CuNi but wondering what it would be. On the Mohr's s scale Copper is a 3 and Nickel a 4 so I would think the CuNi alloy would be harder than the copper core and I would think, if it was dipped in acid or ?? that the copper core would be eaten away first.
As you can see from the photos the 'dime' has detail with more on the obverse and the reading can be felt along the edges. But there is plenty of defects in the surface of the item. Any ideas on what was done to the coin to get it to this state?
Thanks in advance and have a great day!