Slabs & Toning question

anablep

Okay, I've got a few questions I'm just curious about.
Is it possible for toning to occur to a silver coin while it is in a slab?
Does it take longer to occur due to less air circulating around the coin?
Will the rims tone first?
Will the humidity of the surroundings affect slabs as much as a raw coin?

Or have coins not been slabbed long enough to really know the answer?

Thanks guys.

lordmarcovan

<< <i>Is it possible for toning to occur to a silver coin while it is in a slab? >>


Yes.


<< <i>Does it take longer to occur due to less air circulating around the coin? >>


Probably, a little bit.


<< <i>Will the rims tone first? >>


Usually, from what I've seen.


<< <i>Will the humidity of the surroundings affect slabs as much as a raw coin? >>


Probably not, though humidity will have an effect on both. The average slab offers partial but not complete protection.

relayer

LincolnCentMan

Sorry to hear about big kitty.

David

MoneyLA

About a year or so ago I wrote about some rainbow toned proof washingtons -- slabbed -- in which the toning "grew" over larger surfaces of the coins over a period of several months.

At the time, some others here on the board suggested that the coins had some "contamination" prior to slabbing that continued to tone the coins after slabbing.

cheers, alan mendelson

majorbigtime

Sorry to hear about big kitty.

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What happened to Lucy????

SYRACUSIAN

<< Is it possible for toning to occur to a silver coin while it is in a slab? >>


Yes.


<< Does it take longer to occur due to less air circulating around the coin? >>


Not necessarily. It is no secret that many coins develop some fabulous toning especially in pre-2000 ANACS slabs. I have quite a few myself, that were white when submitted.

BillJones

Most coins that tone while they are in slabs do so because there was a contaminate on them when they were placed in the container. When a silver coin tones very rapidly it is almost always due to the fact that the piece had residues of a dipping solution on them. Also cleaned copper coins will tone more rapidly because the exposed metal is more sensitive to contaminates in the air. (Yes, many of the red and R&B copper coins that are in slabs have been played with to some extent to give them some color.)

Since slabs are not airtight, toning can be expected to form over time. But the process should be delayed given that the slab cuts down on the circulation of air around the coin, and given the inert nature of the materials in the slab.

Shamika

The best you can do is keep your slabs in a cool, dry location. Heat is worse than humidity.

anablep

Thanks guys.

I have some pre-2000 ANACS slabs and the Morgans have some really nice peripheral toning on them... nothing coving the coin, but just enough to make them interesting. Maybe they'll tone even more in the future.

robertpr

I have an article laying around somewhere where someone actually did an expirement with this, where they placed the coins in some ziploc bags with some sulphur...

I think what they found was that raw coins toned in about 15 minutes to an hour depending on the coin.

The older slabs allowed coins to tone in about three days, and the old PCGS rattler some rediculous amount of time like a few hours (I'll check it later tonight to verify)

The newest PCGS and especially NGC slabs took more than a week and only allowed very very minor toning around the rims.

dorkkarl

i suspect (high) tempertature would be more significant then humiditi, etc. however, that's speculation on my part. i haven't owned any slab near long enough to know what long-term exposure would do to the coin!

K S

DanArgent

I'm still a little confused on the subject. Is toning a desirable feature on a coin?

LAWMAN

DanArgent: When toning is pretty, it is good. When it is fugly, it is bad. What is pretty, is a far more difficult question to answer. Look at old threads and look, look, look at toned coins at coin shows and in auction catalogs. You will get a sense of what others think has eye appeal -- that's what makes them valuable. But, some eye appealing toning is artificial. Learn how to tell the difference; it's important.

topstuf

Making a slab airtight would not be a good thing. For one thing, the coin could die and for another, no one would ever have to replace a slab and....um...what? I got a call on the other line from HRH and I'll get back to this later....

BillJones

<< <i>I'm still a little confused on the subject. Is toning a desirable feature on a coin? >>



It all depends upon what the toning looks like.

On silver coinage, which are the coins that get the most play, colorful rainbows and other hues that are viewed as attractive can add hundreds or even thousands to the value of the piece.

BUT, the dull brown ugly tarnish, toning that as gone too far - to the point were the luster is gone - and artificial toning are all negatives.

To learn what's good and what's bad, you need to look at a lot of coin in person and listen to those who have knowledge and experience. After a while most collectors do develop an "eye" for the good stuff athough for some it never works out.

Nysoto

In his 1999 article "Slabbing Circa 1840" Russ Logan describes an uncirculated bust dime that was sealed in blown glass around 1840. He described the dime as having medium gray toning over luster. Logan believed this coin to be as original as can be found in an inert environment with a bust coin, and still developed toning. This confirmed his belief that over 99% of bust coins have been messed with.

ddbird

Yes coins can tone in a slab...Like said before..if it is attractive to the eye it will get a premium..but a spotted..dark or ugly tone will decrease the value of the coin!

ms70

My rule of thumb on this: Treat slabbed coins the same as raw coins.

dragon

<<<Most coins that tone while they are in slabs do so because there was a contaminate on them when they were placed in the container. >>>


This is incorrect information IMO. It is now common knowledge that the older thick NGC holders and the older ANACS holders definately caused silver coins to tone, not contaminates on the coins prior to slabbing.

I have quite a few of the very early generation thick NGC slabs containing silver dollars that I submitted MYSELF that are now significantly toned, and these coins were not in any way contaminated or dipped prior to submitting them. It is now actually unusual to see a silver dollar or other siver coin in an old early generation NGC holder that is NOT toned to some degree. The most common type of toning seen on these coins is rim toning in various stages, with some coins toning over completely. The most common colors seen are dark electric blue, a rust color, and various shades of burnt gold, or a combination of all three.

Since the great majority of silver coins in these early generation NGC holders have significant rim toning (which is often seen as splotchy and irregular), it is my opinion that something in the inner white core where it contacts the coin caused the toning, possibly some type of chemical or oily plasticizer or something.

The next time you're at a show and come across a group of silver coins in the early thick NGC holders, see for yourself what I'm talking about........chances are most of them will be toned around the periphery at the very least, and probably in shades of dark gold, rust, and/or dark blue.

dragon

edited to add: As far as the old first generation PCGS holders, it's been my experience that many of the large (untoned) silver coins now seen still in these holders have a somewhat less than lusterous brilliant look to them, or to be more specific, they have a somewhat greyish overall cast. IMO, I attribute this to the fact that the first generation PCGS holders were not even close to being relatively airtight, and exposure to the environment over the past 17-18 years has caused many of these coins to take on a somewhat dull appearance. I also think it is now unusual to see a very lusterous looking blast white large silver coin in a first generation PCGS holder.

Shamika

I believe Dragon is correct.

While the plastic used for slabs (probably Polymethyl Methacrylate) is inert, it is very difficult locating truely pure grades of any resin (plastic).

The vast majority of resins are manufactured with all sorts of additives to not only improve various material properties (UV resistance, static buildup, impact strength), but also assist in the forming process (injection molding). Some of these additives used to help during injection molding include antioxidants, mold release agents, melt flow enhancers, and heat stabilizers.

What affect these additives might have on coins I haven't a clue, but I am rather sure they are not inert.

anablep

Fascinating stuff.

Makes me want to search out some older holders and just check out the toning just to get an idea of the pattern (if any) that results from being holdered for long periods of time. Kind of makes a good arguement against cracking out some coins...