Grading Question: Peace Dollar MS65 with Milk Spots

I remember in an interview with Sight White stickering, they said they don't sticker any coin unless it's at least 10 years old. If the coin (specifically American Silver Eagles) doesn't get milk spots in 10 years, then it is believed to be stable. I would assume if the milk spots we see on Peace dollars are from the mint's process, then any spotting would have become visible long before third party grading services.

 

Log in or Sign up to hide this ad.

Oh my! This topic actually goes deep because it involves chemistry. So, yes, one would expect a Peace dollar that is 100 years old to stabilize, but in practice that's not what happens. The toning is a protective coating, and when it is stripped out from chemical dipping (as is commonly done), you remove some of the surface metal and perhaps make the milk spots more visible - and the microscopic contaminant within the metal potentially more prone to reaction with the environment. I'm just throwing this curve ball because I have wondered if there could be a chain of events involving both chemical contamination at the mint and generally accepted preservation techniques that inadvertently make the milk spots more visible. I believe these spots are almost always on lustrous uncirculated coins. Now maybe I am talking out of my you-know-what as a non-chemist, but ChatGPT just told me this is possible. Anyway, this is getting a bit theoretical.

 

Milk spots in the sense that we are talking are the result of improperly rinsing the dip from the coin. A milk spot like what we see on moderns is part of the coin, this isn't the case for peace dollars. Milk spots are not imbedded in the coin, they are on the surface of the coin. Removing luster does not make a spot appear.

 

No, the milk spot is not inside the coin, but the silver chloride, or other contaminant, causing the milk spot could be embedded within the coin as the planchet is pressed by the die. This contaminant could become exposed as the outer layer is stripped, in theory.

It is my understanding that toning can absolutely cover up a milk spot on a silver coin. Again, stripping away the toning can make a milk spot "reappear" according to my online sleuthing. You'll notice that these milk spots are almost always on bright white uncirculated coins. This means the toning is concealing it on circulated coins.

 

My hypothesis as a dilettante-wannabe-nobody is as follows:

Given that Peace dollars were produced in the early 20th century, it's likely there were some contaminants in this early industrial process. Likely the main culprit is silver chloride in the rinsing, though there could be other culprits. Silver sulfide, or what we regard as toning, can develop over the silver chloride, effectively concealing the contaminant. As coin surfaces are altered with chemical dips, the silver chloride is re-exposed at the surface. This would explain everything we see in a coherent way. Again, I am open to being corrected.

 

Check this out: https://forums.collectors.com/discussion/405221/the-myth-of-milk-spotting

And this: https://www.cointalk.com/threads/milk-spots.68713/

 

I am thinking it is also something the mint did to cause this. I just looked at several Peace Dollars at auction and the photos looked good (strong luster) but upon zooming in, there were some of these small spots (not always but more often than I would have imagined).

 

I am not gonna find myself buying a spotted Peace, There are to many on the market to choose, for a type. I probably would have chosen to buy that coin un dipped, A mistaken choice of a young collector.
It's always gonna be a give and take of Am I making it better?