Cleaning Coins And Value.

Sap. Amazing summary! And alot of good points all around. Good reading. Helpful opinions. Thanks much

Ouch, that's not good. That hurts to read!!! If you ever go to sell those whizzed coins, their value has been reduced to the cull category. The look of the XF-AU cleaned cents in your type set is a killer for me, I would never purchase coins looking like that, and most serious collectors would not either.

Silly question, can a dip into a sonic jewelry cleaner with a drop of dish soap and 2 cups hot water be unacceptable?

My wife is bugging me to do it.

A sonic cleaner may damage a coin if whatever the coin is resting on becomes abrasive from the vibrations. I suppose it would be okay if you held it on edge with tongs to suspend it in the solution.

I highly doubt that would work. A cleaned coin could've been rubbed with an abrasive cloth, giving it hairlines and removing any kind of toning. Placing it in your pocket will have the same exact effect. The coin will be rubbing against the cloth of your pants all day, essentially "cleaning" it. Sometimes it is difficult to tell if a coin has been intentionally cleaned, or just been circulating in people's pockets for a while.

Ultrasonic baths are another excellent example of a cleaning technique that sounds good and harmless in theory, but in practice may be less so.

In theory, suspending a coin in an ultrasonic bath should indeed be an excellent way of removing "dirt", and even lose corrosion, from a coin's surface. The problem comes with practicality: how, exactly, do you levitate a coin in the middle of the liquid? Because unless you're filling the bath with liquid mercury, the coin isn't going to float. And anything solid that touches the coin - the base of the bath, a plastic tray or rack, or even a piece of string tied around the coin - is likely to create a friction spot, as the coin rapidly moves back and forth across that object as a result of the sonication. And, as we all know, for a coin, "friction" = "wear" = "not good".

Now, for a bunch of coins that have been (for example) dug up with a metal detector and are covered in literal dirt, an ultrasonic bath will probably do wonders; a few friction spots is nothing, especially when such coins are highly likely to "be cleaned coins" no matter what you do to them. But for normal coins pulled for circulation or sitting ina collection, an ultrasonic bath can only do harm, not good.


Of course they have; "artificial circulation" of damaged coins by turning it into a "pocket piece" happens all the time. It is especially prevalent amongst "lowball" collectors who are aiming to make their worn, damaged coins as low a grade as possible yet still be identifiable and gradable.

Obviously, you need to wear a harshly cleaned coin down several grades below the "details" grade before the damage from cleaning becomes invisible; if a coin has "EF details", you might need to wear it all the way down to Fine. In effect, this is usually how the market treats the value of cleaned coins: "how much extra wear and circulation would this coin need before the damage becomes invisible?"; the coin is then valued at the grade at which the coin theoretically becomes "legitimate" again.

And in terms of submitting a pocket piece for grading, you might need to leave it on the shelf in the kitchen for a couple of months, to allow it to "retone naturally"; fresh pocket-toning on a 100+-year-old silver coin looks un-natural to us today, since these coins shouldn't be seeing "circulation" any more.