Is It Better To Clean Coins Or Leave Them Alone?

what about if the coin can't really been seen because of so much crud on it, but you know you can clean it. Would it be wise to clean it just enough so you can see the coin?

It's always better to leave the coins uncleaned.

Spider, I cannot stress this enough.

DO NOT CLEAN YOUR COINS! if you care about the value of them. The only exception is a mild cleaning to get rid of surface dirt and oil. But any sort of polish, dip, or whatever that removes toning greatly reduces the value of your coins. Cleaned coins are considered unoriginal, tainted if you will.

Acid cleaners to remove the crud will also take the top layer of the coin and it will flake off leaving a very undesired appears. It actually turns you coin into a Cull. That happened once to an Indian Head cent that I tried to clean up as a kid. (years ago) But taught me a lesson to share with others. If I need to remove some grime on the surface, I use a little method that works most of the time. It is not for BU or PROOF Cents Just circulated wheats to remove some debris that you want to see under. You need an old, retired full cleaned tooth brush and mineral oil. Remember if you try this on a BU/Proof coin it will be messed up for its life. But on a circulated coin it will remove most of the grime from the surface. So use it one something that you need to see under. It is a little time consuming, but not as harsh as cleaners or acidic other processes. Here is a Before and after of a Copper Coin that I treated just 1/2 to show the difference.



I've only used this process for copper coins. This removes dirt, grime and if it doesn't come off I may try a second time. But if it doesn't come off the second time, it probably won't. You might try a fresh thorn to remove little pieces of debris around/inside numbers, but remember this debris may contain sand and will scratch the surface of the coin. So don't scrub this into the coin. I refer to this process as bathing rather than cleaning as one thinks of the acid process when you say cleaning. Mineral oil acts as a protectant to copper, but need to dab off as much as possible. If you don't, they out they will attract dust and more dirt. I usually put my coins into a 2X2 when finished, but if there is some mineral oil residue left on the coin, it will appear wet in appearance.
The procedure I use requires you hold the coin and brush from different angles on the coin. Rotate several times to brush all angles. Repeat till it looks like you want and check under a scope to see problem areas. If you see that more attention is needed in some areas, retry again. If it doesn't come off the second time, then it may not as it is a stain in the copper or green moisture spot or black copper spots that will NOT Come off. All we are taking about removing is surface dirt/oil & grime. Again let me stress: Do not use on a BU coin or a Proof Cent. You may scratch the coin where you don't want it scratch. Also using a very worn out, very soft toothbrush and mineral oil. This will take some time and after bathing press dry and do not rub as you might scratch the surface. I use a plain facial tissue pressed onto the coin to absorb the mineral oil. Time consuming, but the results are nice to you can see what is under the gunk.

Here is one I bathed, but forgot to take a before image. But it looks real nice.

In most cases they are right. If you don't know what you are doing, you can cause more damage than good. So always try experimenting on regular circulation coins before you ruin one of your valuable coins. But that is why I call it bathing. It removes the dirt without ruining the metal on the coin.

I agree with everyone about NOT cleaning coins. But I'm curious about olive oil. I know there was a thread a long time ago about this, but I don't remember much about it except that the examples were copper. So I took some Pre-1980s cents from the change in my pocket and left them in a bowl of olive oil overnight. I also put in a cent that I got from change another time that was black, corroded, almost unrecognizable, but you could see the date (1930). The 1930 coin looks the same. The others may be a little glossier, but that may just be the oil, even though I was able to remove what seemed like all of it. Does anybody have any info on this?