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Copper / Nickel Alloy Question - Copper Dime

ElKevvoElKevvo Posts: 3,984 ✭✭✭✭✭

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!







  • FredWeinbergFredWeinberg Posts: 5,673 ✭✭✭✭✭

    Badly environmentally damaged surfaces.

    Not an error coin of any kind or type.

    could have been in the ground for many years

    Retired Collector & Dealer in Major Mint Error Coins & Currency since the 1960's.Co-Author of Whitman's "100 Greatest U.S. Mint Error Coins", and the Error Coin Encyclopedia, Vols., III & IV. Retired Authenticator for Major Mint Errors
    for PCGS. A 49+-Year PNG Member...A full numismatist since 1972, retired in 2022
  • ElKevvoElKevvo Posts: 3,984 ✭✭✭✭✭

    Thanks Fred. Yeah I would have a hard time even turning it in at a bank due to it's condition!


    ANA LM
  • rickoricko Posts: 98,724 ✭✭✭✭✭

    Wow... that is REALLY bad.... Fred has nailed it.... I cannot imagine what that coin has endured. Probably dropped in the Coinstar by a metal detector person. Cheers, RickO

  • BillJonesBillJones Posts: 33,033 ✭✭✭✭✭

    The copper-nickel alloy turns black or dark brown when it is corroded. This is something collectors should realize when they are buying five cent nickels or the copper-nickel cents that were issued during the Civil War period. If the coin is black or brown, that's not good.

    Retired dealer and avid collector of U.S. type coins, 19th century presidential campaign medalets and selected medals. In recent years I have been working on a set of British coins - at least one coin from each king or queen who issued pieces that are collectible. I am also collecting at least one coin for each Roman emperor from Julius Caesar to ... ?
  • ElKevvoElKevvo Posts: 3,984 ✭✭✭✭✭

    Thanks Bill. That makes sense and I did not know that. So the CuNi is still there but it has corroded and turned brown so sort of looks like it might be copper only but is not. That explains a lot as to the remaining detail, reeding etc. along with the pitting.

    Thanks everyone as always!


    ANA LM
  • 1Bufffan1Bufffan Posts: 603 ✭✭✭

    That one spent some time in the Ocean on a Beach and may have been found by a Metal Detector and Dumped in the coinstar machine to redeem.

  • MarkW63MarkW63 Posts: 1,532 ✭✭✭✭

    That is certainly a metal detecting find.
    Its VERY common to find clads like this metal detecting.
    It the early stages of this the clad turns a rusty reddish color, it certain soils with higher acidic content and longer exposure you'll get what you have.
    Sense I started detecting in the early 80's I've seen many of those.
    Keep your eyes peeled for Copper Quarters :D What causes this is liquid tumbling the clad along with pennies. I've spent a good number of them just for fun, clerks almost always takes a second like at a copper quarter, I've also seen them being sold on ebay for error coins :D
    Detectorist for the most part try to clean our clad modern change before we cash it in, I know many use the coinstars, but I've always rolled mined and took them to the bank.
    We recover tons of lost coins every year.

    "I Prefer Dangerous Freedom Over Peaceful Slavery"
    Thomas Jefferson!

  • MarkW63MarkW63 Posts: 1,532 ✭✭✭✭

    These were recovered in milder soil, so the dime is so pitted.
    I don't have a lot of examples because I've not done much detecting sense the last time I cashed out.

    "I Prefer Dangerous Freedom Over Peaceful Slavery"
    Thomas Jefferson!

  • moursundmoursund Posts: 3,207 ✭✭✭✭✭

    @MarkW63 said:
    These were recovered in milder soil, so the dime is so pitted.
    I don't have a lot of examples because I've not done much detecting sense the last time I cashed out.

    Mint error: "Baby Pac-Man Collar"

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  • Agreed, your coin looks like it experienced 'Environmental Damage'

    Occasionally a planchet is struck and escapes the Mint without the clad layer, often just on one side.
    Several state quarter issues showed this error, I have a NH quarter missing the clad reverse.

    Most who are familiar with maintaining boats will be familiar with replacing 'sacrificial anodes',
    blocks of zinc that reduce corrosion on more critical metal components.

    US cents, post mid 1982, are zinc cores with a thin copper shell, toss one in salt water, and in a short period of time, all that is left is a hollow copper foil shell, with all the shallow strike details of these newer issues.

    I try to leave all my post 82's in the red tray, and am always pleased to find a few deeply struck coppers in my change.
    I'm surprised there's still any in circulation, they are worth 2+ cents scrap last time I checked.
    (Which was a long time ago)

    Desire is oft more pleasant than acquisition.

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