Storage can have an effect

Coins can change color as a result
Published : 06/12/12
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On April 17, the Professional Numismatists Guild membership voted to adopt a definition, below, for “coin doctoring,” or the changing of the appearance of a collectible coin by various processes.

“Coin doctoring refers to the alteration of any portion of a coin, when that process includes any of the following:

“1) Movement, addition to, or otherwise altering of metal, so that a coin appears to be in a better state of preservation, or more valuable than it otherwise would be. A few examples are plugging, whizzing, polishing, engraving, ‘lasering’ and adding or removing mint marks.

“2) Addition of any substance to a coin so that it appears to be in a better state of preservation or more valuable than it otherwise would be. The use of solvents and/or commercially available dilute acids, such as Jeweluster, by qualified professionals is not considered coin doctoring.

“3) Intentional exposure of a coin to any chemicals, substances, or processes which impart toning, such that the coin appears to be in a better state of preservation or more valuable than it otherwise would be. Naturally occurring toning imparted during long-term storage using established/traditional methods, such as coin albums, rolls, flips, or envelopes, does not constitute coin doctoring.”

In my opinion, this is a good start. However, it is dangerous to make too many rules lest those making them be trapped in a corner. “Long-term storage” is mentioned, but how long is long? And, what about “short-term storage”?

In my December 2010 column, I mentioned that I had just received a newly-struck silver medal and was looking at it in my office when a visitor came in. I opened a drawer on a recently purchased oak side table, placed the medal there, and closed the drawer and forgot about it. A month or so later I opened the drawer to see the most beautiful electric blue toning imaginable. Was this artificial toning? What do you think?

Old-timers know that silver coins kept in cardboard Raymond “National” or Meghrig holders tend to tone inward over a period of time. This is due to the presence of sulfur in the cardboard. “Album toning” or “halo toning,” as it is sometimes called, can add great value to a coin. Realizing this a dealer told me that he took bright silver coins, mounted them in such holders, then put them in an oven set at a temperature somewhat over 100 degrees. Beautiful rainbow toning resulted after a short “baking.” Was this artificial toning? What do you think?

Q. David Bowers is chairman emeritus of Stack’s Bowers Galleries and numismatic director of Whitman Publishing LLC. He can be reached at his private email,, or at Q. David Bowers, LLC, Box 1804, Wolfeboro, NH 03894.

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Older Comments (2)
This all sounds so illegal and dangerous! But of course considering how much coins potentially can be worth given their state and appearance, I'm not surprised if there's some sort of syndicate dedicated to manipulating precious coins and historical money just to make sure they get a better deal for it. But where are we going to draw the line about what you can and can't do to preserve and care for your coins? whats a collection if you don't at least take them out to clean and polish once in a while right? Surely that would be allowable?