What happens to toners in 100years?

[SilverEagleCoins]

Whatever is happening to make coins tone, how long does it keep happening. What happens 100 years from now? Will it stay toned? Will it continue to tone?

[LucyBop]

If a coin is in a slab I don't know how much more toning will occur, I don't know if the materials in the slab are inert....

 

My take on toning is that its a protective oxide that has grown on a coin as a result of a chemical reaction.. Usually O2, Sulphur, N2......... and even H20 react with the Siver (AG) of the coin....

 

A grown oxide really slows down as it grows because a oxide doesn't like growing ontop of itself...... This is true in the Semi-Conducter world.... which is why we do a pre-dip to eliminate any native oxides prior to growing a critical quality oxide....

 

I've seen many road tar black and ugly coins with a heavy layer of oxide growth, I surmise that these coins were exposed to heavy quantitys of sulphur or other reactants for a extended period of time.... So I suppose if the conditions are right, they can turn black and ugly...

[nwcs]

If a coin is completely removed from the toning source, then nothing will happen. Otherwise it will continue to tone at a reduced rate directly dependent upon the contamination.

[TomB]

A naturally toned coin should stop toning once removed from the source that initially caused it to tone. An artificially, accelerated toned coin can keep on toning and can turn an uneven, splotchy dark color.

[Beijim]

A naturally toned coin should stop toning once removed from the source that initially caused it to tone.

 

Good.

 

An artificially, accelerated toned coin can keep on toning and can turn an uneven, splotchy dark color.

 

Excellent.

 

Beijim

 

[SilverEagleCoins]

Wouldn't that be something if toned coins had "peak" periods before they turned dark or black? In addition to key dates, strike and tone colors you would have to consider age or the color process!!

[nwcs]

Naturally toned coins do have peak periods of vibrancy (not that the peak for each individual coin will be attractive) and all coins (if left with the toning source) will turn dark over time. But once removed from the environment, naturally toned coins stablize. And are extremely unlikely to change for a very long time.

[TomB]

I agree with nwcs in that coins definitely do have a peak of ripeness, so to speak, after which they are generally considered too dark or dull. Many of the original, cardboard double Mint Sets of the 1947-1958 era have coins that are beyond their peak in them.

[Newmismatist]

I agree with nwcs in that coins definitely do have a peak of ripeness, so to speak, after which they are generally considered too dark or dull. Many of the original, cardboard double Mint Sets of the 1947-1958 era have coins that are beyond their peak in them.

 

Tom's got it nailed. Coins with "active" Metals (i.e. copper and silver) will continue to react with oxygen & sulfer ions to form Cupper oxide, silver sufide on the surfaces of the coins (there are other chemicals that they will react with - someone with a chemistry degree could probaly list all the various 'ides that these two metals can form depending on their respective storage environment). The cardboard and paper in those 47-58 mint sets is a high sulfer content paper AND the paper rests right on the coins surface, so the sulfer continues to react with the silver and eventually it forms a thick non-light reflecting - thus black - silver sulfide on the coin. Doesn't do the copper penny any good either. So if you left those coins in their "originial holders" for 100 years, all you'd get would be black ugly coins - (the nickels might survive a little better). If you removed them form the holders, say 5 years after they were placed in the holders, you "might" have a nicely toned coin. While at Long Beach I looked at about 10 "original" early 50's mint sets. Best way to describe them: "Fugly"- the toning was very dark & mottled, my guess is that the toining had etched the surface of the coins, and nothing could be done to "curate" them. In other words if they were dipped, you'd have a dull, lusterless coin.

 

The same will occur if silver coins sit in brown coin envelopes unprotected by a plastic (non-pvc) insert. They will eventually tone very dark, & unattractive if left long enough. But somewhere between putting the coin in the envelope and that black coin there is a nicely toned coin. maybe somewhere between 6 months and 10 years - it will all depend on the sulfer content of the envelope.

 

The trick to stopping the toning is to take the coin out of the environment that causes the toning. So a slab should keep the coin from toning further, UNLESS there is something on the coin that will cause the metal to react with the foreing substance - sometimes, all it need be is a small speck of dust that - If you look hard enough, you will see silver slabbed coins that develop "spots" while in the holder - and close inspection will often reveal a speck of dust (or something foreign) sitting on the coins' surface. With copper, you'll sometimes get an active growing green spot that will actually eat into the coin.

 

Bottom line is to check your coins, slabbed or not, regularly to make sure nothing bad is happening to them

[EZ_E]

Lots of excellent responses!

 

All toning is just an intermediate stage between fresh mint state coins and dark, completely toned coins. The rate of oxidation depends upon the variables affecting the coin, i.e. environment, storage, etc. The complete transition to full oxidation can take anywhere from a few decades to a few hundred years.