Fingerprints On Coins ... Odd?

Human skin exudes a natural oil to keep it supple.
If a brand new copper surface comes into contact with fingers once only, the prints are left behind and the residue oil, over time, will react with a copper surface. Visible finger prints will be left behind. These finger prints can be impossible to remove, because the oil in the skin is really a type of fatty acid, and has reacted with the metallic surface.

If a coin is handled a great deal, all these finger prints from many people get merged into each other, evenly.

To demonstrate that skin exudes an oil, put your hands in a mild caustic solution. The result is that your hands will feel soapy. What has happened in this case, is that the oil has reacted with the OH ions of the alkaline caustic solution, and actually have produced a sort of 'soap'.

What has really been produced is that an insoluble. oil has been converted into a soluble oil, which is what a soap really is. your skin will feel dry because the oil has beeen strippd out of your skin.

Which is why bleach feels slippery on your hands.

Isn't sebum earwax, come on your me out

If you have ever been to a stripper bar in Asia you would NEVER put a coin in your mouth

The real reason no fingerprints on all coins is due to almost everyone now using Latex gloves all day. Then too many wear other types of gloves to keep their fingers warm.
Others wash all the coins in their pockets each night.
And remember that dead people don't give off those oils and acids on their fingers either. Coins in your pocket get rubbed all the time by cloth.
So if you eliminate people wearing gloves, dead people, coin washing people, coins left in cloths and put into a washing machine, few coins get fingerprints.
And of course with all the adds today about stopping germ spreading by using those germ things in almost every store, even less prints.
At this rate a coin with a finger print will be worth more.

Or joe dirt lol

just carl => wow, you may be correct!? I'm gonna try to sell a few coins on the web, as

=> Mint State, with possible "celebrity-fingerprints"



trout1105 => I'm not exactly sure if an Asian stripper counts as a celebrity, but there would probably be a niche-market for your dirty stripper coins as well?

In an attempt to drag this thread kicking and screaming back to the original question...


They do. They don't have a "whole bunch" of nice clean sharp fingerprints because more than a couple of fingerprints overlap to produce an overall broken-lustre effect.

It's like footprints on a beach. If it's a beach where there's only ever been one person walking on it, it's easy to see only one set of footprints, nice and clear. Two or three footprints are still easy enough to track, though it might get confusing in places. A couple of dozen people or more and the sand just becomes cratered with overlapping footprints to the extent that you can't really see any distinct sets of footprints at all.


We coin collectors have a word for that. It's called "wear". We collectors generally don't like wear, whether it's mechanical wear from friction or chemical wear from reacting with fingerprint oil.

It's not the actual fingerprint that causes permanent damage, it's the chemical reaction between the slightly acidic fingerprint oil and the metal of the coin's surface that causes the problem. Which is why it's recommended that, if you know you've accidentally put a fingerprint on a coin, wash the print oil off with a solvent like acetone straight away, before the reaction can begin. Let the oil sit there long enough to make a visible print (for example, dark brown on a bright copper coin) and it's too late for acetone to do any good; you might wash off the residual oil but the metal has already reacted with it.

I have a Bermuda cent I purchased as a YN, one of my first coins. I'm sure it was uncirculated back when I first got it, but now it's more of an EF, from my handling it carelessly a few dozen times and from being stored in a PVC coin page a bit too long.