What Happened To This Massachusetts Quarter Proof?

It's either toning or brown reflection from the table it's sitting on.

That is a beautiful toning .

Soooo... I guess my EYES are also effected by the table?

I need to try and take a pic when (if) the SUN comes out today, without any flash or artificial lighting.

BUT so far it IS toning, and NOT unusual? I assumed slabs were indeed air-tight!

This toning phenomena is nutty...

EDIT: I actually DID correct the white balance a bit as the original photos were too blue. Again, I will try again when natural lighting is better.

Toning can occur while in the proof set holder, it's not completely airtight.

MOS0239 - (rimshot) ;-)

The sun still isn't out today so I probably still can't get a better photo.

I did look around The 'Bay yesterday after turkey and there are indeed many proof quarters that seem to have at least similar toning, but this one is so darn even!

I wonder... is there anything in the NGC code that can help with figuring out roughly when a coin is graded? That would (maybe) help with what Conder101 said, that maybe it was already toned when slabbed.

EDIT: https://www.NGCcoin.com/certlookup/4304196-046/69/
Is it me, or does it almost look toned in their reference images? Did that hologram decal even exist in 2000?

my 1999, 2000 2001 silver proof sets all toned in a manner like this, I assume the other sets will follow as well. the mirrored fields will tone different from the frosted devices (including the rim edge which is frosted too).


And it's toned on NGC look up, you can see it on the left of the state although they didn't highlight the toning and took a dark picture instead.
so it was like that when they slabbed it. it doesn't hurt anything at all. mine started as a slight milky haze you could see tilting in light, and developed to a yellowish/brown which will develop further colors as time progresses and allowed to continue, this stage is one of the ugliest really and where people back out of toning and dip them.

people sleep through this usually and come back in a decade or so more and look again or find them toned up further along than this, this is early still and only year 20 :)
up to you, dipping would remove it, you could stop it where it is with climate control and better storage practices to remove sulfur, or air, or moisture from it's storage environment.

or you can let it go and do it's thing as nature intended it to and check back later and see where it is.

and technically the toning isn't "even". It's just not "spotty" at all which is really good, but it is darker toward the edge of the coin than the center, which is totally normal. as the toning gets thicker it will reflect different colors from wavelengths of light off the surfaces. It won't just go from this gold/yellow/brown to black, it "should" kick over to blue, red and purple around the rim in towards the center next but depends on what the contaminant was that started it (usually sulfur and some mild humidity).

Nothing wrong here at all, unless you just personally don't like it, which is a preference. eventually this will color up though and get even better with time.
Also I'd like to add it's well centered, a lot of time the toning forms from one direction inward or one side, so the "toning ring" is partial or seems to be off centered.

It used to be they would not tell you when a particular coin was slabbed but they have been getting better at providing that information on request.

As far as I know, they do not do use that designation on any coins.