What gives coins blue toning?

Discussion in 'Coin Chat' started by William F, May 16, 2021.

  1. William F

    William F Well-Known Member

    I'm sure this is not "natural toning" but I am curious to know how they get like this? Any thoughts? I've seen this not just on copper but also on silver coins... 20210515_155746.jpg 20210515_155821.jpg
     
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  3. Morgandude11

    Morgandude11 As long as it's Silver, I'm listening

    Definitely artificial toning. Copper coins rarely tone with this color pattern. This toning job is so sloppy—it looks like it is coated, and baked on.
     
  4. SensibleSal66

    SensibleSal66 U.S Casual Collector / Error Collector

    Ohh Nooo ! More Pee Pee Stains ?? Artificial from where ?? Another planet ?:hilarious:
     
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  5. William F

    William F Well-Known Member

    LOL, I think these look really cool, I haven't found anybody else yet who does tho...
     
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  6. Lehigh96

    Lehigh96 Toning Enthusiast

    The reason they don't like them is because the toning is artificial. There are plenty of collectors who will say that they don't care whether toning is artificial or not, but few collectors are able to maintain that indifference when it comes time to sell them.
     
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  7. Silverpop

    Silverpop Well-Known Member

  8. longshot

    longshot Enthusiast Supporter

    Sulfur, heat, and other chemicals
     
    William F likes this.
  9. Randy Abercrombie

    Randy Abercrombie Supporter! Supporter

    We did have a CT member that did an unplanned experiment several years ago. He had put his proof set and forgot about it for several weeks left in his car in the Dallas summer sun. The plastic package was twisted and looked that it had been in a fire and the coins did develop that rainbow looking toning.
     
    William F likes this.
  10. ldhair

    ldhair Clean Supporter

    The early PCI slabs and some of the cheap plastic holders are known to tone coins blue. I don't believe that's the case with the OP coin. I'll guess heat caused it's blue look.
     
    William F likes this.
  11. GDJMSP

    GDJMSP Numismatist Moderator

    Simple answer - chemicals. And chemicals can be applied in liquid form, gaseous form, and even powdered form. And if you know which chemicals to use and how to apply them properly you can make coins any color, or combination of colors you want.
     
    William F likes this.
  12. AuldFartte

    AuldFartte Well-Known Member

    I love blue toning! I have some NT mostly from English collectors/dealers. I think those ones have something to do with storage methods/album types. The US blue coins I have mostly appear to be NT, but I do have an AT Franklin half.
     
    William F likes this.
  13. Lehigh96

    Lehigh96 Toning Enthusiast

    So do I, especially on Rosies and Franklins, but I prefer toning that looks natural as opposed to the coins in this thread which is best case scenario were treated with MS70 coin cleaner.

    [​IMG]
    [​IMG]

    To me, it is the combination of vibrant blue & violet together that screams AT across almost every series of coin.
     
  14. rte

    rte Well-Known Member

    WD40 or lite oil and heat.
    Just like chrome side pipes.
     
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  15. TheFinn

    TheFinn Well-Known Member

    Na2S or K2S.
     
    William F likes this.
  16. Razz

    Razz Critical Thinker

    Some series and dates are known for blue toning such as the 1960s proof nickels. I cut this one out of the original mint proof set package myself. Before and after pictures. DSCN0571~2.JPG DSCN0572~2.JPG DSCN0742~3.JPG DSCN0743~3.JPG
     
  17. GDJMSP

    GDJMSP Numismatist Moderator

    While I understand your point re "best case scenario", and while MS70 is notorious for turning copper a shade of blue or purple, I think it's important for others to be aware that it's a near certainty the OP coins in this thread were not treated with MS70.

    MS70 pretty much always results in a natural looking toning when used on copper. A look that is as different from these coins as night is from day.
     
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  18. calcol

    calcol Supporter! Supporter

    Different colors can be, and in the case of “natural” toning almost always are, produced by the same chemical. Usually it’s hydrogen sulfide. The different colors are due to diffraction differences which, in turn, are due to differing thicknesses of the sulfide layer on the coin.

    Cal
     
    Last edited: May 18, 2021
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  19. charley

    charley Well-Known Member

    Cobalt dust.
     
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  20. AuldFartte

    AuldFartte Well-Known Member

    Here's that Franklin I mentioned. AT or NT?
    1958 Franklin Obv.jpg
    1958 Franklin Rev.jpg
     
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  21. Lehigh96

    Lehigh96 Toning Enthusiast

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