What if anything do you know about using chemical and/or physical analysis to detect "artificia

ANACONDA · February 22, 2006 8:20AM

What if anything do you know about using chemical and/or physical analysis to detect "artificial" toning?

mgoodm3 · February 22, 2006 8:31AM

When you dip the coin, if the toning is removed, it was real.

MORGANHUNTER2 · February 22, 2006 8:32AM

Send it to a forensics lab, and have a spectrometer test run on the coin. they can run a composition check and tell you what was used to 'tone' the coin.

Steve27 · February 22, 2006 8:35AM

I've heard that with a very good microscope you can see the depth of the toning on a coin. Shallow toning would be an indication of AT (i.e. deep toning takes time). I don't know if it's true, and it would take a very expensive microscope to find out.

mozin · February 22, 2006 8:47AM

I know that encapsulated coins cannot be tested.

relayer · February 22, 2006 8:56AM

Only Frattlaw can scientifically detect AT.

Everyone else has to rely on their experience.

Anyone who tells you differently doesn't know what they are talking about.

stev32k · February 22, 2006 8:59AM

That sounds like a research project to me. I'm not a specialist in metals analysis, but I am a chemist and chemical engineer and your question is something I've looked into in the past. My conclusion was that I don't know enough about the toning process, and the published scientific information is sparse and not based on controlled experiments. There are no answers to the question of why some coins will tone faster than others under what appears to be the same conditions. Or, why two seated liberty dimes placed in the same envelope for the same period of time and one tones mostly blue while the other turns mostly red.

If you find any answers it would be worthy of publication.

Rob790 · February 22, 2006 9:00AM

<< I've heard that with a very good microscope you can see the depth of the toning on a coin. Shallow toning would be an indication of AT (i.e. deep toning takes time). I don't know if it's true, and it would take a very expensive microscope to find out. >>

"Depth" (if you mean thickness) of the film is no idication of real or fake.

It's a thin film process and thickness, film composition along with the film's refractive index will determine the color. Any variation in thickness will be nominal and not a determining factor.

Perhaps you are refering to some other definition of 'depth' as in do the colors float. Do the colors have 'depth'? but that is too subjective and not a reliable means of detection if 'depth' can be duplicated in the colors.

Fairlaneman · February 22, 2006 9:04AM

Visine is a chemical and it clears the eyes up so a person can see correctly. Thats all I know.

Ken

p8nt · February 22, 2006 9:12AM

I know that MrSpud can make pretty AT coins.

cladking · February 22, 2006 9:15AM

The way we define AT and NT it is impossible to scientifically differentiate them
and always will be. It would be possible to create a database that would identify
specific batches and some of major individual techniques.

Rob790 · February 22, 2006 9:19AM

<< What if anything do you know about using chemical and/or physical analysis to detect "artificial" toning? >>

I don't think it is as difficult as many say. It is about analyzing the film on coins known to be 'natural' and comparing it against artificial toned ones.

In theory, a simple table top optical spectrometer could be used to analyze the composition of a thin film and then a reference chart made to compare against other films and compositions for various coins and film types (copper, nickel, silver, gold... etc.). Then when a coin in question comes up, the charts should closely match.

Of course, real life is not that simple (like when a natural coin gets enhanced - where you get a purposely grown film on a natural film). No real scientific studies of coin films have been made. It really wouldn't take much money for the equipment, probably under $5000.

All that is missing is someone with the technical knowledge and time to make these charts and know what they are looking for and what they are doing. A whole certification service could be started that actually verified natural vs questionable or outright AT coins. I don't know why the major services don't do this. I should do the leg work, develop the method and sell it to them.

I am making a BIG assumption here, that the film's composition is different in some manner. Seems reasonable (since many say that AT films are neon like and not as lack depth - probably as issue with film contamination where the AT ones are TOO clean and not as 'dirty' as a natural one) but as I said, there has been NO real scientific research into this field and certain assumptions need to be made until someone actually does the leg work to prove otherwise.

THE other part that is just as important is knowing the correct look for a coin. More subjective but if someone can duplicate a 'natural' film, they still have to get the right look.

There really is no reason that AT coins should not be determineable. Besides the fact that there has been no REAL scientific work in the field.

Rob

TwoSides2aCoin · February 22, 2006 9:26AM

<< Visine is a chemical and it clears the eyes up so a person can see correctly. Thats all I know.

Ken >>

that's funny Ken

... it only clears up the eyes so people think the person using it is thinking correctly not seeing correctly

dragon · February 22, 2006 9:42AM

<< What if anything do you know about using chemical and/or physical analysis to detect "artificial" toning? >>

This topic was discussed in depth several years back by a few experienced coin people and a couple of experienced chemists as well.

The conclusion was that any means of purely scientific chemical or otherwise physical analysis would produce inconclusive and spotty results at best under every possible scenario.

It's my position that the absolute best possible tool you can have is extensive experience and nothing more. Unfortunately for many collectors as well as dealers, experience is not something you can purchase.

SUPERCARCOINS · February 22, 2006 9:47AM

..i believe PCGS uses spectoligy ;specificly, ultraviolet light rays

to help them detect A.T coins

LickThoseStamps · February 22, 2006 9:50AM

I gather if one is selling its NT. If buying its AT. Am I missing something?

carl · February 22, 2006 9:51AM

I'll throw my 2 cents into this one. Also a chem major I don't think there is a chemical method to determine AT or NT. There are just to many variables. I myself have tried numerous tests to just try to tone coins. I've tried to bury some in the dirt, some in envelopes, in a jar with eggs ( wow did that stink after a week) H2S you know, on the stove, in the stove, in a bar-b-que, under my arm pit and many other places you wouldn't believe. As an experiment it was naturally required to put at least 2 similar coins in the same situation. Numerous times the coins reacted (toned) slightly differently. I just went up to the gutter of my house today to retrive two Quarters that have been there for Months. They had no toning and looked better than when I put them there. We must remember that toning is a form of tarnishing and that indicates a chemical reaction with a contaminate in the facinaty of the coin. For instance a copper coin beginning to tone in an area where there is an abundant quantity of Sulfur Oxides in the air but low moisture content (Low Humidity) to absorb the SO or SO2 radicals may tone very slowly. If suddenly the contaminates stay the same but the moisture increases, so dose the acidity. Therefore, toning may be different in different locations, time of day, day of the year, altitude of the coin on Earth, type of coin, possible coatings on the coin from handling, etc.
It becomes obvious that since toning is different per coin that determination is also just a good guess at best.

lloydmincy · February 22, 2006 9:57AM

<>

Yes, the sellers saying it is NT. Here we go - now everyone, including an "expert", wants to know how to tell the difference. This get's better everyday. What a joke.

Anaconda - PR damage control? Tail between your legs? You're making yourself look worse by asking the question, no???

Just someone who believes no one has a true 100% clue. Life goes on.

BlindedByEgo · February 22, 2006 10:01AM

<< ..i believe PCGS uses spectoligy ;specificly, ultraviolet light rays

to help them detect A.T coins >>

Mebbe they need one of them thingies acrost the street

Lakesammman · February 22, 2006 10:05AM

Sounds like a leading question (ie: trap) to determine that there really isn't a scientific way to determine if, for instance, a Peace Dollar is AT or NT.

Best way is to post the coin here and let the "experts" decide.

BlindedByEgo · February 22, 2006 10:08AM

<< Sounds like a leading question (ie: trap) to determine that there really isn't a scientific way to determine if, for instance, a Peace Dollar is AT or NT.

Best way is to post the coin here and let the "experts" decide.

>>

Oh, Jeez, and I'm up there tryin' to be nice... And you come along... Now look where we are going.

Popcorn, anyone?

ANACONDA · February 22, 2006 10:19AM

I know the art world suffers from some similar problems.

Here's a link that was sent to me that might be of interest:

link

Barry · February 22, 2006 10:26AM

<< Visine is a chemical and it clears the eyes up so a person can see correctly. Thats all I know.

Ken >>

Sorry Ken, but you know one less thing than you think you do. Visine is a vasoconstrictor. It has no effect on vision.

dragon · February 22, 2006 10:33AM

<< I know the art world suffers from some similar problems.

Here's a link that was sent to me that might be of interest:

link >>

Interesting read, however there's a significant difference between the two.

relayer · February 22, 2006 10:43AM

<< I know the art world suffers from some similar problems.

Here's a link that was sent to me that might be of interest:

link >>

All toning is natural. You can build the Gaunkulator2™ to detect the green marble sitting on the floor. It just can't tell you how it got there.

Rob790 · February 22, 2006 11:08AM

<< 

<< What if anything do you know about using chemical and/or physical analysis to detect "artificial" toning? >>

This topic was discussed in depth several years back by a few experienced coin people and a couple of experienced chemists as well.

The conclusion was that any means of purely scientific chemical or otherwise physical analysis would produce inconclusive and spotty results at best under every possible scenario.

It's my position that the absolute best possible tool you can have is extensive experience and nothing more. Unfortunately for many collectors as well as dealers, experience is not something you can purchase. >>

"Discussing something" is not conclusive of anything. In science, only doing the actual leg work and looking at real data from spectroscopic scans could any of any real conclusion be drawn. Admittedly, some coins may be still be iffy but the majority of AT jobs could possibly be detected.

I completely agree with the last sentence. The best tool is experience... and as far as scientific testing for AT coins goes, I've yet to see anyone with any REAL experience in this area (charts and actual data) and all I hear are half drawn conclusions, not the way science is done.

No one can really speak as to the real validity of scientifically being able to determine the true nature of a coin's film until someone does the work. It can only be put forth as a possible means that is as yet untested.

Rob

What if anything do you know about using chemical and/or physical analysis to detect "artificia

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What if anything do you know about using chemical and/or physical analysis to detect &quot;artificia

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What if anything do you know about using chemical and/or physical analysis to detect "artificia