Do toned coins continue to "tone" after slabbing?

maddox

Does the toning on a coin stop once it's removed from whatever source started the process? Does slabbing a coin inhibit future toning?

Just purchased my first toned coin, nothing spectacular but I liked the way it looked.

I've got my eye on a sweet Morgan anaconda has listed. I'll know later tonight if it's going to be my newest addition to the obsession...

nwcs

They can continue to tone, but at a very slow rate. It will likely not change in your lifetime. Assuming the toning was not created by liquids or gas (acting as a liquid), which changes the equation some.

tracker

Not if the slab is air tight. Many older slabbed coins, when placed in the wrong environment (or right environment if you like toning) will start or continue to tone. Do not store older slabs in cardboard boxes if you hope to arrest the toning process.

nwcs

Even with air tightness, if the toning agents on the coin are not neutralized, it will continue to tone.

BillJones

The main reason why coins continue to tone after they are slabbed is that they have been dipped and not properly rinsed. When this happens the changes the changes can be dramatic and in coin terms pretty rapid. The results can also be quite ugly.

For coins that have a nice original toning, given proper storage, (away from chemicals like sulfur, even temperatures etc.) the coin should not change much if at all over you lifetime.

coinguy1

MANY toned coins continue to tone AFTER they have been encapsulated. Untoned coins often tone, as well.

Whatever oxidation process might have begun before a coin's having being "slabbed", sometimes continues afterwards

It is also my understanding, that even with airtight holders, gases can be absorbed through the plastic and this can lead to oxidation / toning.

There are a number of products on the market that can inhibit the oxidation process. Perhaps someone can post links to some threads on the subject?

Placid

You mean intercept shield's Mark?
Link

For me none of coins have toned yet. My red wheat cents are still bright red after 15 years.
I guess I must live in the right area.

dorkkarl

no question about it, especially if dipped or cleaned.

dipping/cleaning strips off the oxidized layer of metal. that oxidized layer, having already reacted chemically w/ air, etc, is relatively neutral, & not prone to further toning. if stripped off, that exposes the "unreacted" layer, kind of like the next layer of an onion. being "unreacted", it is far, far more susceptible to toning.

that's why i am adamantly against dipping of any coin, except to remove even more-harmful pollutants.

furthermore, as terrific a job as the plastic co's have done in researching inert holders, it is essentially impossible to create "inert" plastic, therefore the plastic itself will react w/ the metal in the coin. but pcgs/ngc/anacs/yes even acg, have done a terrific job of using plastic w/ a low level of reactivity.

K S

truthteller

In general, the reaction of surface metal to an environment, whether it be a sulfur envelope or a Wayte Raymond holder, will cease once withdrawn from that environment. However, air and heat will continue to affect the coin and the process of oxidation but to a much less degree. If you have humid conditions, the environment may still reek havoc with copper coins, dryer conditions less so, and so on. Holders are not air tight, so coins traveling around the country meet different atmospheric conditions at various times. Many dealers and collectors will not travel with copper coins to humid environments due to these concerns.

TRUTH

ANACONDA

I have had a few toned coins in holders for over 2 years and in that time it doesn't seem that any of them have changed at all, but that could be simply because a slight change wouldn't be noticed by me.

I have a few white coins that i've had for the same period of time and they have developed spots. Nasty spots. They were cheap coins (two proof washington quarters that were minted in the year of my birth and the year of my wife's birth, so they're fairly new coins, slightly over 17 years old.)

adrian

P.S. From what i understand, the intercept shield thingies work by surrounding the coin with stuff that the gases get worn out by.......essentially, the gas is essentiallly "used up" by the intercept shield stuff so that the gas is de-gassed by the time it gets to the coin. Or something like that. Obviously i'm not Phd'd in chemistry.

nwcs

Them 17 years snake years?

ANACONDA

Yes, 17 snake years.

Dog97

coinguy1 forgot to mention that his old company, NGC is well known for having a blast white coin develope cool periph tone, especially at the part of the coin near the paper insert from the older holders.
Other than that slabs pretty much inhibit the toning process.

JoyofCollecting

Weimar White wrote an excellent article in issue #70 of the Gobrecht Journal describing his experiments in determining whether or not coins will continue to tone after being encapsulated. An additional article on these experiments was published in July 8, 1996, edition of Coin World.

In a short paragraph the conclusion was:

"Collectors should know that coins may continue to oxidize and show an increase in tarnish levels while stored in their slabs. Last year Coin World commissioned an experiment by this writer to demonstrate that slabs may not be airtight and that coins may continue to tone after encapsulation. There had been reports from collectors that some of their slabbed coins were changing color during storage."

The article further goes on to basically conclude: All coins will continue to tone in slabs. However, some services' slabs will continue to tone much more rapidly than others. Most importantly; the content of the surrounding air (or gases) that the slab is exposed to will have a greater impact upon the speed and extent of additional toning. In other words; the most airtight slab in an environment that has a low content of sulphur will show little visible additional toning over a long period of time. However, other companies slabs exposed to air with a high sulfur content will tone in a matter of days.


Hope this helps.

Crashtestfixer

place a coin in inert atmosphere (should hault oxidation),!? already existant. the metal will create its own atmosphere if already active, tombed or raw.


avb