Naturally Toned Or Artificially Toned? 1925 Peace Dollar

The point of using the term in this case is that the toning process is not binary, it exists on a continuum with varying degrees of human intervention. While some are obvious, many are difficult to prove if they are natural or artificial. We once had a debate whether or not artificial toning had to consider intent.

Benny w, I am so pleased that you are happy with your purchase. The only way to truly judge a coin is with it in hand!
Cableguy815, one of the major problems with AT'd coins is they are not usually stable the way a naturally toned piece is. 5 or 10 years down the road it may look very different from what you originally bought, and not in a very pleasant way. I have less of a problem with those who are honest with what they are doing, at least there is no deceit involved (just ruined coins). To me, it is no different than the cheap Chinese fakes or an added mint mark, the collector who ends up with them is the one that gets stung at the end. Again, JMHO.

Naturally toned ..

Toning should continue as long as the coin remains in the environment that caused the toning.

It never really stops, because these metals are reactive. However, it can slow down if you make an effort to isolate the coin from the environment.

Very interesting, Ssuperdave. I hadn't looked at it that way. Times like this I really miss Mike DeFalco, he had so much knowledge and was so willing to share. I would love to have heard his thoughts on this.
If a coin was gassed to produce the toning (especially in the holder), would there be a residual left on the coins surface that would promote continued toning? If the toning is induced through an applied liquid (like an ms70 on copper), would not any residual left have the same effect? As far as heat, I don't know.
Just some thoughts, can't say I have ever messed around with any of this, and most of what I have learned has been from people who have been around for much longer than I and whose opinions I respect.

or is it perhaps that he has a brother that works at PCGS?

I'm reaching into the theoretical here, because I only know enough chemistry to get myself into serious, unrecoverable trouble.

Toning is a chemical reaction, requiring the presence of two or more interacting chemicals. Any reaction which continues after the initial "application" is proof positive that all those ingredients remained present, whether it be residual stuff left gaseously wandering the inside of a slab, or deposited on the surface, or even introduced during poor-condition storage afterwards. I think it safe to say that only Morgans have a sizable percentage of toning artifacts created during Mint storage; pretty much all the rest of "NT" adjudications are subsequent to the circumstances under which "civilian" owners of the coins held them - atmospheric conditions, storage media.

Coins change hands, and the circumstances - and relative moral purity - of the owners differ. The simple fact that intent can be the only determiner between "AT" and "NT" remains, because the physical laws of chemistry are unchanging. Whether you do it deliberately or not, the color only comes from a specific chemical process. Even if done deliberately, done right there is absolutely no way to tell the difference, and the only reason we can identify coins as "AT" is if the person doing it either uses flawed technique or has too little patience.

If you're willing to take a month about it instead of 24 hours, and choose your subjects carefully, 90% of your deliberate work will be NT because it can't be differentiated from NT. Fortunately for us, too few of the miscreants are willing to put in the work.

So the proper definition of toning is "market acceptable" or "not." Neither you, I or anyone else can tell when it's deliberately done right, because there is no physical difference.

Here's a couple of examples for you. First, a poster child for what MS70 is thought to do to copper (and a hint about the role photography plays in evaluation):









AT, or NT? Blue, or Brown? I'll never know for sure; I've only owned it for a few months of its' 102 years of life. I_do_know that I willingly paid more for this coin, raw, than any of my other LC's....who cares if it was MS70'd, or not? It is hands-down the most beautiful coin I own. Here's Number Two:





That one's pretty as well, in a far more subtle way. And there is no question in my mind that it is AT by more conservative definition, lacking only that I didn't intend it to acquire the color. It acquired the color completely since being in my possession, and only because the surfaces had been stripped prior to my acquiring it. I'm sure, because it arrived in a CCCS slab, and looked like this 9 months ago:







I cracked it from that slab, and stored it with the rest of my LC's, in the same SaFlip and the same box as the rest. Over the summer, it toned. None of the other coins - including that 1915 - showed the slightest change, yet the 1859 turned. Rather attractively, to my eye.

AT, or NT? And, considering the two entirely different "looks" of the 1915, can you believe your eyes?

One final thought since this thread started out with a Peace dollar. Peace dollars are a very different bird than Morgans, and they tend to tone very differently. I can't put it in better words than Sunnywood, so let me quote both him and David Hall.
Anyone who has collected colorfully toned silver dollars finds out sooner or later that Peace dollars just don't come like Morgan dollars. (Even 1921 Morgans are different from prior Morgans in terms of rainbow bag toning). There were differences in alloy, planchet preparation, burlap Mint bags, and the history of storage in bank vaults.

No less than David Hall himself has written the following:

Note that I am of the very strong opinion that any 1921 Peace dollar...indeed any Peace dollar...that has any rainbow colors (blue, red, green, etc) is absolutely artificially toned. While not very scientific, my approach to toning on coins is to remember the colors I saw in the 1960's and 1970's and if a new look appears, it's artificial to me. This is kind of an "old school" approach and I may be wrong, but unless you believe global warming has created new colors for coins, it just seems illogical to me that new colors would suddenly appear naturally on coins.

-- David Hall, PCGS Coin Facts, in his comments on the 1921 High Relief Peace dollar

I believe that there are some out there, but they are very rare.