Toning thesis.

There is no sometimes about it, all coins tone, period. At the very moment that a coin leaves the dies it begins to tone. But there are many, many degrees of toning. And at first it is a very slight change where the freshly minted silver color turns just a tiny bit darker. And it progresses from there.

Actually every worn silver coin you have ever seen was toned. Yes, the toning may have been removed if the coin was cleaned or even harshly cleaned, but before the cleaning was done the coin was toned. It is impossible for it to be otherwise.

However, I think when you say "I rarely see worn silver tone " what you really mean to say is "colorfully tone ". For example, here are some pics of worn silver dimes.

http://www.google.com/imgres?hl=en&...nh=160&tbnw=315&start=0&ndsp=17&tx=234&ty=104

http://www.google.com/imgres?hl=en&...bnh=181&tbnw=175&start=0&ndsp=17&tx=107&ty=96

Both of those coins are toned to different degrees. But they are toned the most common color of toning there is for silver - grey. People often forget or at least often don't refer to grey colored coins as being toned, but they are.

Now I think this is more along the lines of what you are referring to -

http://www.google.com/imgres?start=...&page=8&tbnh=183&tbnw=189&ndsp=27&tx=34&ty=88

http://www.google.com/imgres?start=...age=8&tbnh=183&tbnw=190&ndsp=27&tx=148&ty=113

That worn silver coin has some color to it. And yes it is unusual, but certainly not unheard of, for worn silver to acquire colorful toning.

Toning not only can occur, it will occur. Since all coins are exposed to the air the moment after they are struck, and since there is no such thing as an airtight coin holder, any coin that is exposed to the air will absolutely tone, to at least some degree.

As I said above, toning begins the moment a coin is struck. And it continues as the coin enters circulation. The vast majority of the time that toning is going to be grey in color. And once a coin has toned to a certain point that toning does provide a layer of partial protection that slows down any future toning, but the toning does still continue. But it is the toning providing the protection, not the skin oils, dirt & grime. On the contrary, skin oils, dirt & grime cause toning, speed it up, but that toning it is pretty much always grey in color.

It is also normal and inevitable that as a coin goes through circulation that toning on the high points of the coin is worn away through wear, thus exposing fresh metal that will tone yet again, and be worn away, tone again, etc etc. That is why when we look at worn silver coins the high points are lighter in color and the protected areas are darker in color. For the toning in the protected areas is not worn away so it becomes progressively darker as time passes.

Yes, this is true, the metal will tone much faster on a worn silver coin that ha sbene cleaned or harshly cleaned than it will on one that has not, at first. The toning process starts all over again, but since the worn silver coin has no luster that toning will not be nearly as fast as it is on a freshly minted coin. And once the toning reaches a certain point, the toning itself again becomes a protective layer and slows down additional toning.

Bottom line, worn silver coins tone much slower and it is much less likely that the toning will be colorful. It does happen, just not very often. That is because the color is largely attributable to luster.

To better understand this I suggest that everyone read what is found at these links -

http://www.cointalk.com/threads/what-you-need-to-know-about-the-science-of-toning.84670/

http://www.cointalk.com/threads/luster-a-guide-for-beginners.58435/

http://www.cointalk.com/threads/morgan-toning-vs-peace-toning.12578/

 

Rick is correct, toning does not remove signs of harsh cleaning, it merely covers it up so the signs of cleaning are less easily seen. The signs of harsh cleaning are still there under the toning.