It doesn't look natural to my eyes and I would be very surprised if either grading service graded that coin. To start, I have never seen that type of target toning on a Peace Dollar. While the progression from yellow-magenta-cyan is correct in the mid rings, the first color present should not be a dark color. Furthermore, the elevation chromatics are a big indicator of AT. When the colors creep over the lettering and devices like that, it should cause immediate suspicion. I don't think this coin is market acceptable, and I think this is artificial toning created by a very good coin doctor.
Thank you for your diagnosis. If you follow the link: http://images.goldbergauctions.com/php/lot_auc.php?site=1&sale=31&lot=618&lang=1 This is what finally convinced me that mine is actually true toning.
1922&1923 Philly a lot stayed in bag's or a bank would roll up some for customers. I know that's what was done at my grandparents Bank.
FWIW, I do not have nearly the expertise lehigh has, but your example more convinces me your coin is AT. As he stated the inside color should not be dark.
I have concerns about that coin as well but the toning looks more market acceptable than yours. When evaluating toning, you need to try to determine what storage conditions could have caused the resultant toning pattern. On the Goldberg coin, the obverse shows what is called target toning creating concentric rings of progressing colors that are more advanced at the rim of the coin which was in contact with the sulfur rich paper of the album that housed the coin. So if the coin was in an album, why did the obverse tone almost completely, but the reverse developed no toning whatsoever? That said, the toning on the obverse of the Goldberg coin looks much more market acceptable than yours. First, the color progression starts at the center of the coin with tan an progresses gradually to orange, lavender, and powder blue which is a common progression. Your coin starts with an untoned interior and then has a defined dark ring to start the toning progression. I have seen this toning pattern before and it usually appears on artificially toned ASEs. Second, the toning on the Goldberg coin does not creep over the lettering with the same consistency that it does on your coin. Whenever I see a common date low grade silver coin with little to no numismatic value and dramatic rainbow toning that shows many elements of AT, I become very suspicious of the originality of the toning. Your coin is no exception. But I am not a grader at NGC or PCGS and I have not seen the coin in hand. In order to reap any financial benefit that the toning would provide this coin, you are going to need to get it certified, so my suggestion is that you submit the coin to either PCGS or NGC for certification.
Target toning or not, if some fool paid that kind of money for a common '23 they need to have their head examined.
Btw, the Goldberg photo looks saturated to me. I used to collect toned Peace Dollars and I don't ever remember coming across one with colors that vibrant.
Here is a photo I took of a Peace dollar with similar toning. The coin is owned by a PCGS member. Photo was taken 5-6 years ago. No toning on the obverse.
Pretty Peace Piece, but IMO it's AT. It's the sort of coin I would have bought at essentially untoned coin price.