How did this even grade?

That cobalt blue/cyan color is definitely the correct shade. Plus the toning progression should go gold-magenta-cobalt blue-cyan-green-yellow-orange-red, which is exactly what is seen on my coin. They don’t have the POP you’d expect since the coin had been harshly cleaned and had no luster.

Edited

I think you need a review of what NT and the color progression looks like:

 

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I gave into my curiosity, and I tried looking for such a post. I could only find one other time I posted that coin, and you did not comment in that thread. I guess it was a comment in another forum

 

I cannot believe I ever would have said the 61 Quarter even closely resembled NT. Those colors are completely wrong. If you can find the post where I said that, I'll retract my previous statement.

And, as I said a few posts ago, NT Morgans and NT Peace dollars are going to have very different appearances. You really can't compare them.

 

I think a lot of why the colors look wrong is that I lot the coin using a bright yellowish light to brighten the coin, and that the coin was previously harshly cleaned. The colors were not as vibrant in-hand. The color progression is correct. The process I used to tone the coin was completely natural (though “induced”) so the colors should understandably match the progression.

 

I posted the Morgans as an example of the color progression being exactly what you said it is not, and as an example of the “blues” which you said were impossible (note the 1882). I was not trying to compare them to peace dollars.

 

Show me ROYGBIV

 

I sold this coin a few years ago so I can’t get a true in-hand picture of it, but this is about how I remember it looking. There were areas in the fields that had extremely thin layers of patina, so they appeared silver in color (A). Then around these areas was gold color which would transition to yellow (B-D). This yellow would transition to burgundy ar the base of the letters and immediately around the eagle (E-F). This would then transition to cyan in the inner half of the letters (G-H). This would then transition to a greenish yellow (I). And along the inner SE rim, there is some transition to yellow and orange (J-K). The progression is followed.

 

OP, you wanna see unbelievable toned peace dollars......look at some PCGS registries. You'll see ones that make this peace look like nothing

 

TC, be honest now. You can't really compare the putrid shades of your AT'd coin to the vibrant hues of the Morgan.

And, as you seem to be familiar with Sunnywoods coloring scheme, you know that he goes through about 3 cycles of the color progression. The first cycle is the lighter pastel tones, the second cycle is the bright, popping colors that get so much attention, and then the third cycle is the darker, more subdued tones. The 79 you post here is a great example of a nearly full set of all three cycles. The S, J, and C areas are all yellowish - but clearly they are different shades of yellow. That is because as the silver sulfide layer gets thicker, it is going to change the absorbent properties. The color you see is based on the mathematical relationship between the thickness of the layer and the wavelength of light.

The blues on your AT'd coin and the blues on that 1882 look absolutely nothing alike. I'm sorry if you can't see that.

I thought this thread was about toning on that Peace dollar? Maybe I'm confused on what we're arguing about, then?

 

I looked through them all. Here are the top four nicest. Note how they look completely different from the original coin (they look natural!)

 

I searched the Heritage archives for Star graded Peace dollars (figured that would be the easiest way to get some of the nicest toners.) I present, as counterpoint, quite a few pastel colored coins. The 25 in 66+* especially has a pretty similar look to the OP, in my eye:

 

That is because the Morgan has luster while my coin does not. The colors on my coin look wrong because of the lighting and the surfaces. Check out this coin. Same “putrid” lifeless colors with the same (correct) color progression.

I am very aware of the physics of thin film interference when it comes to coin toning. My coin and the Morgan are subject to the same laws of physics. My coin was stored in a sulfur-rich environment for three months and acquired a layer of silver sulfide. By the laws of physics it should follow the same color progression as the thickness of the sulfide layer changes. And it does as I have demonstrated. The progression goes through the first of the three cycles. I’m sorry if you can’t see that.

Here is a spreadsheet I made where I explored the mathematical relationship:

The argument is about the natural progression and patterns of toning. My quarter has it, even though it was artificially induced. The above quarter has it, at it probably is not “naturally occuring” either. The morgans and supplementary Peace dollars have it, and they are all likely completely natural. The OP Peace dollar does not.

All of those have a pattern while the OP coin does not.

 

Alright man, there's no more point arguing. It is clear that neither of us is going to convince the other. You take your 61 quarter, I'll take the peace. We'll each call the other's AT'd.

 

Sounds good

 

Morgan dollars tone more beautifully than Peace dollars because the Peace dollar planchets were given a more concentrated acid bath at the Mint. Reid Goldsborough (2013) http://rg.ancients.info/guide/toning.html