MS70 conservation on copper - what does it do? Final summary posted!!

[MikeInFL]

Interesting results thusfar that correlate with my own experimentation very well.

 

Question #1: Why use soap & water on the coin to begin with? Wouldn't a less reactive "wash" in something like acetone make for a better downstream test?

 

It just struck me as odd that you would have started out with a wash with soap -- typically a base that presumably (and in my experience) reacts with the coin in a destructive way.

 

I'm not sure it has any bearing on the results but I did think it worth mentioning.

 

Question #2 (maybe a better question for after your results, but I'll ask it now): Did you weigh the coins with precision enough to ascertain if something was actually removed or added to the coin by the application and subsequent removal of MS-70?

 

Question #3: Did you do any analysis of the composition of the untreated coin in terms of the "red" and "brown" areas that react differently to MS-70. For instance, did you notice a "film" of copper oxide or copper sulfide where we saw "brown" and pure copper in the "red" areas?

 

Question #4: Now, based on your own direct experience with the substance, do you think your Randall Hoard coin was MS70ed?

 

I look forward to the rest of your experiment and results & thank you for taking the time to do them. Take care...Mike

[Hard Times]

So what can be concluded about MS70? Does it react with copper or does it remove materials on metal surfaces, or both? No question from the results shown here it is removing material. So the question then becomes, does it also react with copper? To answer this, we need to know at least two things. First, what is MS70? Second, what reactions would take place and what would be the products?

 

So to answer the first question, my first step was to perform a pH test. I use the pH meter here in our lab at work that uses a glass electrode that is dipped into the solution for which the pH value is measured. I obtained a pH of 13.7 (ultrapure water is 7.0) for the MS70. This is extremely basic and not acidic like dips which will have a pH below 7.0 or that of neutral water. It is essentially some type of detergent and highly oxidizing. There is a very light ‘bleach’ odor, and it has a light yellow-honey color and is fairly viscous

 

This places limits on what it can be:

 

 

Alkaline and basic chemicals in water solutions used in detergents:

 

http://www.engineeringtoolbox.com/bases-ph-d_402.html

 

Ammonia 1N pH =11.5

Ammonia 0.1 N pH =11.1

Ammonia 0.01 N pH =10.6

Potassium hydroxide 1N pH = 14.0

Potassium hydroxide 0.1 N pH =13.0

Potassium hydroxide 0.01 N pH =12.0

Sodium acetate 0.1N pH =8.9

Sodium benzoate 0.1N pH =8.0

Sodium bicarbonate 0.1 N pH =8.4

Sodium carbonate 0.1 N pH =11.6

Sodium hydroxide 1N pH =14.0

Sodium hydroxide 0.1 N pH =13.0

Sodium hydroxide 0.01 N pH =12.0

 

http://en.wikipedia.org/wiki/Sodium_hypochlorite

 

 

Bleach – sodium hyperchlorite – pH = 11

 

It should also be noted, and this is key here, that the solutions using sulfates, and thus containing sulfur as a possible reactant, are lower in pH, and sometimes on the acidic side below the pH = 7 of water. This includes sodium thiosulfates and thiourea (pH 5.0 - 7 at 50 g/l at 20 °C (68 °F)

 

So MS70 is likely to be something containing a highly oxidizing detergent including chemicals like sodium hydroxide. The amount of bleach and ammonia in solution must be low or the pH of 13.7 measured would be lower.

 

 

From the same wiki article on sodium hyperchlorite, here are the types of reactions one can expect with metal using these types of products:

 

Sodium hypochlorite reacts with metals gradually, such as zinc, to produce the metal oxide or hydroxide:

NaClO + Zn → ZnO + NaCl

 

One presumably can substitute Cu for Zn. The outcome of this reaction is CuO plus salt. If such a reaction took place on a coin, then our product is copper oxide.

 

 

In the wiki for sodium hydroxide

 

http://en.wikipedia.org/wiki/Sodium_hydroxide

 

Sodium hydroxide (NaOH), also known as lye and caustic soda, is a caustic metallic base. It is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents and as a drain cleaner. Worldwide production in 2004 was approximately 60 million tonnes, while demand was 51 million tonnes.[1]

 

Cleaning agent

Main article: Cleaning agent

Sodium hydroxide is frequently used as an industrial cleaning agent where it is often called "caustic". It is added to water, heated, and then used to clean the process equipment, storage tanks, etc. It can dissolve grease, oils, fats and protein based deposits. The sodium hydroxide solution can also be added surfactants to stabilize dissolved substances to prevent redeposition. A sodium hydroxide soak solution is used as a powerful degreaser on stainless and glass bakeware. It is also a common ingredient in oven cleaners.

A common use of sodium hydroxide is in the production of parts washer detergents. Parts washer detergents based on sodium hydroxide are some of the most aggressive parts washer cleaning chemicals. The sodium hydroxide based detergent include surfactants, rust inhibitors and defoamers. A parts washer heats water and the detergent in a closed cabinet and then sprays the heated sodium hydroxide and hot water at pressure against dirty parts for degreasing applications. Sodium hydroxide used in this manner replaced many solvent based systems in the early 1990s. when trichloroethane was outlawed by the Montreal Protocol. Water and sodium hydroxide detergent based parts washers are considered to be an environmental improvement over the solvent based cleaning methods.

 

So you can see from this, (if anyone has any more info please share), highly basic detergents, either can scour and clean metal surfaces and remove material, or if the right mix is present, they might produce metal oxides on surfaces.

 

Now let’s see what copper and zinc oxide looks like:

 

http://en.wikipedia.org/wiki/Copper%28I%29_oxide

http://en.wikipedia.org/wiki/Copper%28II%29_oxide

http://en.wikipedia.org/wiki/Zinc_oxide

 

Red, black, and white see for yourself, and they do not have the metallic luster observed and instead will show up dull, not reflective when fine particles on a surface.

 

They are unlike the blue-violet-red regions on copper some say is reaction to MS70. But mixes of these would very likely give us shades of black-brown-red patina, that could react with MS70 and be removed.

 

Now let’s look at copper and zinc sulfide:

 

http://en.wikipedia.org/wiki/Copper_sulfide

http://en.wikipedia.org/wiki/Zinc_sulfide

 

Zinc sulfide in nature is the mineral sphalerite:

 

http://en.wikipedia.org/wiki/Sphalerite

 

‘Its color is usually yellow, brown, or gray to gray-black, and it may be shiny or dull. Its luster is adamantine, resinous to submetallic for high iron varieties.’

 

Again does not fit the bill for blue-violet-red on surfaces on copper.

 

Amongst the potential candidates of copper sulfides that have metallic luster:

 

CuS, covelleite looks like this:

 

http://en.wikipedia.org/wiki/Covellite

 

Does it look familiar? See the blue-violet-red colors?

 

Color:

 

‘Indigo-blue or darker, commonly highly iridescent, brass-yellow to deep red’

 

This is similar to the colors in question.

 

Summary:

 

So what have we learned?

 

1. Detergents with high pH, scour and remove materials from metal. If they were to react with the metal, they are likely to produce oxides.

2. Oxides generally have dull non reflective red, brown, black colors. They do not look like what is observed once MS70 has removed surface patina.

3. One could make the case that in fact, this is part of what is removed from the copper coins.

4. However, simple CuS - covellite, WHICH WILL NOT BE FORMED BY REACTION WITH DETERGENT, has the iridescence and colors seen on copper coins.

 

In summary, the experiments shown above show that things are being removed. MS70, a detergent is not reacting with copper to produce covellite. Instead CuS is likely produced by reaction of Cu on the surface of coins with sulfur in the atmosphere giving them their blue-violet-red tone we commonly observe. So all MS70 is doing is removing material. The choice is yours as to whether you think this is acceptable or not. Similar to acid dipping gold and silver, and acceptable apparently to top TPG’s for grading.

 

[BROADSTRUCK]

Your 1854 1/2c was a real ballsy coin to use on this experiment, yet it now has the signature MS70 color which is commonly seen on the browse floor.

[TonerGuy]

Great research, great experiment and great article. Thank you for all your efforts.

 

Whether people agree or not it was important to see science brought into the discussion rather than speculation.

 

Interesting that you feel that it is akin to an acid dip for silver... I tend to agree.

 

It would be nice to hear NGC's position on the use of MS70 on copper and whether they feel that it would considered artificial toning because of the color variations.

[Hard Times]

Yes it would, but I don't think they are going to weigh in on this.

 

Here is a CWT with blue-violet-red tone, I'll keep it even if patina was removed to bring out the color tones

 

 

This HT also:

 

[Hard Times]

Here is another copper probably conserved with MS70 - blues and violets are not as apparent. Another comment is that while acid dips are likely to dissolve sulfide, oxidizing detergents are less likely to dissolve sulfide and will hence reveal the sulfide toning underlying oxide in the patina.

 

[mhomei]

thank you for your time,experience,and patience this article is fantastic and I think has actually made me a better collector

[MikeInFL]

HT, I would appreciate you answering my prior questions if you don't mind.

 

And here are a few more that came to mind for the sake of an "open, well thought out, dialogue":

 

Question #5: Have you done any surface analysis to see if CuS is actually what's left on the surface of the coin after a dip in MS 70? Some kind of spectroscopy I would imagine would identify the substance fairly quickly, would it not?

 

Question #6: Could it be CuSO4 on the surface? It's translucent blue too.

 

Question #7: You draw the conclusion that "MS70, a detergent is not reacting with copper to produce covellite." Could it be that MS-70, a strong oxidizer, simply removes the toning, and the reactive Cu layer below picks up something -- S or Cl? or K? or ? - already present in MS-70?

 

Question #8: Colorful toning is typically caused by thin film diffraction. On silver coins this is Silver Sulfide. It is a black substance, yet it obviously tones silver all sorts of color because it is translucent when thin enough. Yet, in our discussion above we are focusing not on thin film interference to cause color but rather chemical composition. You suggest a thin layer of covellite, a blue mineral, has been formed. However, when one applies oil to this blue toning, my experience is the color disappears (you might experiment for yourself) -- suggesting it is actually thin film interference rather than covellite's color that is causing the color change. This seemingly calls into question the conclusion that it is covellite causing the color (or that we should care at all what color it is in crystalline form). Can you explain this apparent paradox?

 

Question #9: (#8 asked differently) Could the thin film actually be copper oxide, acting like the thin film of silver sulfide on copper?

 

Question #10: What have you done, outside of exposing a few coins to MS-70 (hardly groundbreaking, and virtually all of your sample coins had a blue hue to begin with -- hardly representative) and a PH test on MS-70 (again, there was little disputing it was a base detergent)? I guess I was expecting something with more scientific rigor and less conjecture given your background and prior commitments. To wit, in a prior post you stated:

 

"I will:

 

1. Measure the pH of MS70, the manufacturer claims it has a pH of 7 and is inert. I found 1 report that claims a pH of 10, which would make it a reactive oxidant.

 

2. Do an ICPMS analysis for composition of MS70 to find what the cations and major anions are present in it. Is there Na for example? Once we know what is in it, we can then explore what chemical reactions may or may not take place.

 

3. Apply MS70 under several different conditions on exactly 1 half of the surfaces of several lincoln cent picked out in varying degrees of visual toning and grunge. Photos of before and after. Depending on the outcomes, I might sacrifice a couple large cents in AU grades I have.

 

4. Do a quantitative analyses of the compositions of the surfaces of the specimens used in the experiment using an SEM. Since we will have only half of each surface conserved with MS70, we have before and after compositional changes."

 

Yet it seems to me all you did was #1 and #3. Did I miss something?

 

Thanks in advance...Mike

[MikeInFL]

[Hard Times]

HT, I would appreciate you answering my prior questions if you don't mind.

 

And here are a few more that came to mind for the sake of an "open, well thought out, dialogue":

 

Question #5: Have you done any surface analysis to see if CuS is actually what's left on the surface of the coin after a dip in MS 70? Some kind of spectroscopy I would imagine would identify the substance fairly quickly, would it not?

 

I have been away for the past week so hence my slow response. This is CuS we are seeing on the surfaces of these coppers has the right color scheme and has metallic luster. Read my summary post, there is no need to go further without additional time which I don't have right now and some funds, otherwise, if I had lots of free time, what you suggest is good.

 

 

Question #6: Could it be CuSO4 on the surface? It's translucent blue too.

 

The picture you show is copper sulfate pentahydrate (CuSO4·5H2O) that is blue in color and is an industrial chemical. It can be made by reaction with sulfuric acid, NOT by reacting with an oxidant like MS70. Another naturally occurring CuSO4 is antlerite (CuSO4·(OH)4, which is black to emerald green in color. This is not the range of colors observed that are the same as covellite. These sulfates have vitreous luster, not metallic as observed in my images. Also if copper sulfate is present on the surfaces, then one can distinguish them from covellite using the hardness test. Covellite has a hardness of 1.5-2 on the Mohs scale, antlerite 3.5-4, if industrial copper sulfate has the same or similar hardness to antlerite (I could not find it) then a fingernail (hardness slightly greater than 2) should scratch the metallic luster if it is covellite, and should not if copper sulfate. Copper has a hardness of 3. So I went and scratched my fingernail above Abe's cabin in the image in the above post. Sho' 'nough, the toning with metallic luster came off and the copper underlying was not scratched consistent with a layer of covellite overlying copper metal. Ain't no copper sulfate y'all

 

Question #7: You draw the conclusion that "MS70, a detergent is not reacting with copper to produce covellite." Could it be that MS-70, a strong oxidizer, simply removes the toning, and the reactive Cu layer below picks up something -- S or Cl? or K? or ? - already present in MS-70?

 

It is a strong oxidizer, I said that, nothing is impossible, but my empirical data indicate that the toning was already there and patina was removed to reveal more toning in some cases. Cl will not combine with Cu to give you the color scheme or luster you want and it has to be supplied by an acid which MS70 is not:

 

Wikipedia:

 

"Copper(II) chloride is prepared commercially by the action of chlorination of copper:

 

Cu + Cl2 + 2 H2O → CuCl2(H2O)2

 

It can also be generated by treatment of the hydroxide, oxide, or copper(II) carbonate with hydrochloric acid. Electrolysis of aqueous sodium chloride with copper electrodes produces (among other things) a blue-green foam that can be collected and converted to the hydrate.

 

Anhydrous CuCl2 may be prepared directly by union of the elements, copper and chlorine.

 

CuCl2 may be purified by crystallization from hot dilute hydrochloric acid, by cooling in a CaCl2-ice bath."

 

If you have chlorine gas you bubble through water containing Cu, you can make it without an acid as shown above, but any Cl in MS70 is bound in a compound, not a gas, and the copper is not in a valence state of 2 in the metal but instead at 0, so you need something to drive the chemical reaction you want that will oxidize the copper metal (yes MS70 is an oxidant) and selectively bond it with Cl with kinetics on the scale of a few seconds. Is this possible? Even if it is, the luster of such a copper compound produced is not metallic, as observed on the images. You could also make cupric chloride through electrolysis as the Wiki article notes, but I did not stick live wires on the coins during conservation with MS70 so you surely cannot suggest this happened?

 

Can you spell verdigris? These compounds you keep wanting the surfaces to have, are in fact what verdigris is - oxides, chlorides, sulfates of copper with dull luster and in some cases green-blue color. NO METALLIC LUSTER for these compounds. This is not what is observed in the images.

 

I have never heard of a CuK mineral. How can you create sulfide using an oxidizer containing small amounts of S? I can't find a chemical equation that would show us this is possible. Can you?

 

Question #8: Colorful toning is typically caused by thin film diffraction. On silver coins this is Silver Sulfide. It is a black substance, yet it obviously tones silver all sorts of color because it is translucent when thin enough. Yet, in our discussion above we are focusing not on thin film interference to cause color but rather chemical composition. You suggest a thin layer of covellite, a blue mineral, has been formed. However, when one applies oil to this blue toning, my experience is the color disappears (you might experiment for yourself) -- suggesting it is actually thin film interference rather than covellite's color that is causing the color change. This seemingly calls into question the conclusion that it is covellite causing the color (or that we should care at all what color it is in crystalline form). Can you explain this apparent paradox?

 

These are thin films (i.e microns thick) bonded to the surfaces of coins, the color that is reflected off the film changes with thickness of the film and the crystallographic orientation, as well as other physical properties of the top layers of the film. So I am not sure why this is a paradox.

 

Question #9: (#8 asked differently) Could the thin film actually be copper oxide, acting like the thin film of silver sulfide on copper?

 

As noted in previous posts, wrong color, wrong luster

 

Question #10: What have you done, outside of exposing a few coins to MS-70 (hardly groundbreaking, and virtually all of your sample coins had a blue hue to begin with -- hardly representative) and a PH test on MS-70 (again, there was little disputing it was a base detergent)? I guess I was expecting something with more scientific rigor and less conjecture given your background and prior commitments. To wit, in a prior post you stated:

 

I remember you asking in this thread for me to show what I did, so I obliged you even though all tasks were not complete.

 

1 was answered, 2 will cost me $75/hour which I am not interested in spending, 3 I did and show the results, 4 also takes time and money, the former which I don't have right now and the latter I don't want to use for this purpose at present. However, I am very convinced that from the experiments I did, in combination with the discussion of properties of potential compounds that could give the blue-violet-red toning with metallic luster as observed, is that the idea of MS70 reacting to cause toning you and others claim as fact is an old wives tale and I don't need to go further. Please note MikeinFl, I have no agenda here, I just want to find out what is going on. Au contraire, it appears as if you do have a agenda as you have shown in your posts on various threads here and ATS with respect to the issue of MS70, you want the toning to be doctoring so you can blame top TPG's of slabbing doctored coins, you have made this abundantly clear. If your suggestions on this are correct, this is a serious deal and I wanted to thus find out since I have copper coins with blue-violet-red toning on them that are slabbed by top TPG's. But from the experiments and discussion I present here, in my view it appears that you are not correct in this and thus I don't feel it productive to do more work on this problem. MS70 removes patina and other matter on the surfaces of copper but does not create or remove sulfides on the surfaces, to remove these, you need acid. The choice is again yours whether you feel MS70 conserved coins are something you want to own, but the observations and discussion I present are what they are.

 

If you disagree, I suggest that you help me to complete my proposed experiments for ICPMS and EPMA/SEM. You could, for example, send me funds for the costs of the analyses. Then I will do them as soon as I can, even though I really don't have the time right now but nevertheless I will go half way on this by you paying and I providing the labor. If this is what you need to further explore this issue, please, pony up and I will do these tests.

 

"I will:

 

1. Measure the pH of MS70, the manufacturer claims it has a pH of 7 and is inert. I found 1 report that claims a pH of 10, which would make it a reactive oxidant.

 

2. Do an ICPMS analysis for composition of MS70 to find what the cations and major anions are present in it. Is there Na for example? Once we know what is in it, we can then explore what chemical reactions may or may not take place.

 

3. Apply MS70 under several different conditions on exactly 1 half of the surfaces of several lincoln cent picked out in varying degrees of visual toning and grunge. Photos of before and after. Depending on the outcomes, I might sacrifice a couple large cents in AU grades I have.

 

4. Do a quantitative analyses of the compositions of the surfaces of the specimens used in the experiment using an SEM. Since we will have only half of each surface conserved with MS70, we have before and after compositional changes."

 

Yet it seems to me all you did was #1 and #3. Did I miss something?

 

Thanks in advance...Mike

[MikeInFL]

Thank you for your response. Frankly, much of the chemistry is over my head, but I do thank you for sharing your thoughts and addressing the issues I rased.

 

On #8 -- The paradox is that when you place oil on the substance you suggest is CuS, the color disappears. If it were the mineral's color, rather than thin film interference, causing the toning I don't think that would occur. Therefore it calls into question your conclusion that it is the mineral's color causing the toning. It is also worth noting other toning still has a "metallic luster" yet comprised of sulfides, Ag2S being a prime example. IMO, this is the biggest single "hole" in your logic outside the fact that you never did the surface analysis you said you would.

 

On #10 -- Please PM me your name, address, and the amount of money you require. I will mail you a check.

 

Also on #10 -- I have no agenda here outside of figuring out the truth. I don't "want the toning to be doctoring". I don't want to "blame" the TPGs for anything. And I challenge you to find anywhere where I've said such things. However, when a person (you!) says they will do four things and leaves out the two that would have authoritatively answered the question at hand, and then arrives at the same conclusion as they had originally made, please pardon me for asking a few questions.

 

Lastly, you failed to address my first four questions. No need to address all of them, as I can infer your answers from the ones you provided above. However, I would really like an answer to this one:

 

"Question #4: Now, based on your own direct experience with the substance, do you think your Randall Hoard coin was MS70ed?"

 

Just curious....Mike

 

p.s. Getting past the scariness that it is that delicate to begin with, I found it fascinating that the blue toning scratched off. That wasn't something I had heard of, tried, or even thought to have tried. Neat!

[Hard Times]

 

On #8 -- The paradox is that when you place oil on the substance you suggest is CuS, the color disappears. If it were the mineral's color, rather than thin film interference, causing the toning I don't think that would occur. Therefore it calls into question your conclusion that it is the mineral's color causing the toning. It is also worth noting other toning still has a "metallic luster" yet comprised of sulfides, Ag2S being a prime example. IMO, this is the biggest single "hole" in your logic outside the fact that you never did the surface analysis you said you would.

 

There is book called 'Optical Mineralogy that I can recommend with a link below but any text on this subject would likely do to explains the use of oil immersion and how it would change the observed tones, hues, colors, etc. of minerals:

 

Optical Mineralogy, Kerr

 

 

On #10 -- Please PM me your name, address, and the amount of money you require. I will mail you a check.

 

I would need around $500 to finish off the work, you willing to send me $500 for this? Plus when I say right away, that is likely to be June at the earliest, zero chance before then I will have the time at work. I will let you know when I am ready to do this and contact you, thanks.

 

Also on #10 -- I have no agenda here outside of figuring out the truth. I don't "want the toning to be doctoring". I don't want to "blame" the TPGs for anything. And I challenge you to find anywhere where I've said such things. However, when a person (you!) says they will do four things and leaves out the two that would have authoritatively answered the question at hand, and then arrives at the same conclusion as they had originally made, please pardon me for asking a few questions.

 

 

 

your words:

 

"Who are you going to believe? A dealer who makes his living selling these coins, or collectors like you?

 

If I'm so wrong, why aren't people contradicting what I say?

 

Could it be that I speak the truth?"

 

The implication is that dealers and TPG's are in cahoots about this, similar to other posts by you to ATS to Rick Snow that I won't post here. But yes I could have overinterpreted the TPG part, but clearly you have a thing against dealers that sell pretty toned copper.

Here is the link: MikeinFl speaks out about MS70

 

In fact, after doing my own tests and observing the results, for which I present above, I am indeed contradicting the old wives tale that MS70 causes blue-violet-red toning on copper. Every single photo above, every single before and after elsewhere, shows that brown patina was removed, free copper surfaces are not affected, and what is underneath is revealed.

 

See for example this set of images by robec who I have great respect for, but disagree with him if he feels that MS70 did more than remove patina. What I note about removal, copper surfaces, and toning clearly is supported by these images;

 

Robec's images of the 1914 lincoln, down the page

 

 

Lastly, you failed to address my first four questions. No need to address all of them, as I can infer your answers from the ones you provided above. However, I would really like an answer to this one:

 

"Question #4: Now, based on your own direct experience with the substance, do you think your Randall Hoard coin was MS70ed?"

 

Haven't a clue, I believe the blue toning to be authentic given my results, clearly, some type of conservation agent has been applied to remove dirt, possibly patina, etc. If not MS70 that won't remove CuS sulfide, it may be that the old EAC way of doing it - xylol followed by blue ribbon was applied to remove grime, won't stop me from loving this large cent that is for sure

 

Just curious....Mike

 

p.s. Getting past the scariness that it is that delicate to begin with, I found it fascinating that the blue toning scratched off. That wasn't something I had heard of, tried, or even thought to have tried.

 

I explained it in the above post don't know what else I can do, so I recommend you read 'Manual of Mineral Science', Hurlbut and Klein, It is in its 23rd edition, originally published by Dana as Manual of Mineralogy back in the day. It will give you information about the Mohs hardness scale and how to apply it as I described in the previous post. I used the 19th edition, published in 1977 for this work. Hasn't changed much since then, but plenty more books to sell for mineralogy classes that are taught in just about every university out there. Toning on surfaces of coins is usually only a few microns thick at best, CuS is softer than a fingernail, oxides are not, copper is harder than a fingernail, the prediction that I tested is thus a fingernail should rub off toning if it is CuS, exposing clean copper underneath, oxide should not rub off with the fingernail. Go try to scratch off brown (if oxide) patina with your fingernail, does not work well, now try it on any coin with very thin sulfide on top of metal, it will work if it is CuS. Simple hardness test used to identify the materials in question. Having said that, you can find images all over the web of blue-violet-red toning that was likely 'lightly scratched/rubbed' off by something that did not harm the underlying surfaces after the coin was toned, making streaks or even less/untoned areas engulfed by the original tone. This is what is expected when the tone is soft like covellite.

 

You can get it here:

 

Hurlbut and Klein

 

Finally, I will repeat a question/comment from a previous post again - why would NCS not tell NGC and possibly PCGS to stop slabbing with grades toned copper like this if it was AT and produced by a chemical? Maybe I am truly naive, but they must have come to the conclusion, doing their own experiments, that such coins are NT. Otherwise the implication is huge and probably this thread will be removed and I will be banned from these boards for even suggesting this. 'Market Grading' can go only so far, if what some claim, which I refute here, is that MS70 tones copper then a serious day of reckoning will be coming soon, amen.

 

I love this copper with tiger stripes and NT and because it was the impetus for this study, I post it here again:

 

[robec1347]

I can certainly understand your thoughts on the two images of the 1914 Lincoln Proofs. The way the post was written would even lead me to believe that I thought MS70 had something to do with the difference in appearance between the two images.

 

When I said

What do you suppose was used on this coin to turn it from the first image to the second?

I didn't mean for it to sound like my conclusion was that the resulting difference was due to MS70, I was actually asking what you thought had caused the change. It has to be some type of doctoring, although I like the before appearance better than the upgraded appearance.

[Yaha]

Here's my question concerning your 1817 coin, why only a 64 grade? Is it because of the color? I think it is a very strong strike looking at the pics, but, again many say you cannot give a accurate grade by a picture.. George

[MikeInFL]

On #8 -- The paradox is that when you place oil on the substance you suggest is CuS, the color disappears. If it were the mineral's color, rather than thin film interference, causing the toning I don't think that would occur. Therefore it calls into question your conclusion that it is the mineral's color causing the toning. It is also worth noting other toning still has a "metallic luster" yet comprised of sulfides, Ag2S being a prime example. IMO, this is the biggest single "hole" in your logic outside the fact that you never did the surface analysis you said you would.

 

There is book called 'Optical Mineralogy that I can recommend with a link below but any text on this subject would likely do to explains the use of oil immersion and how it would change the observed tones, hues, colors, etc. of minerals:

 

Optical Mineralogy, Kerr

 

Thanks, I've ordered it.

 

On #10 -- Please PM me your name, address, and the amount of money you require. I will mail you a check.

 

I would need around $500 to finish off the work, you willing to send me $500 for this? Plus when I say right away, that is likely to be June at the earliest, zero chance before then I will have the time at work. I will let you know when I am ready to do this and contact you, thanks.

 

I meant what I said. PM me when you're ready.

 

Also on #10 -- I have no agenda here outside of figuring out the truth. I don't "want the toning to be doctoring". I don't want to "blame" the TPGs for anything. And I challenge you to find anywhere where I've said such things. However, when a person (you!) says they will do four things and leaves out the two that would have authoritatively answered the question at hand, and then arrives at the same conclusion as they had originally made, please pardon me for asking a few questions.

 

your words:

 

"Who are you going to believe? A dealer who makes his living selling these coins, or collectors like you?

 

If I'm so wrong, why aren't people contradicting what I say?

 

Could it be that I speak the truth?"

 

The implication is that dealers and TPG's are in cahoots about this, similar to other posts by you to ATS to Rick Snow that I won't post here. But yes I could have overinterpreted the TPG part, but clearly you have a thing against dealers that sell pretty toned copper.

 

Here is the link: MikeinFl speaks out about MS70

 

Again, I said no such thing, Hard Times. Not in that post, and not in any post to you. Frankly, I don't appreciate you putting words in my mouth, and it is not the first time. Please stop.

 

If I "had a thing" about dealers that sell pretty toned copper, would I have purchased this coin from one of the dealers on this very forum who specializes in them?

 

 

I am doing what I'm doing because I believe that blue copper, and how it is "revealed" or "made", is the result of exposure to a chemical. Furthermore, this type of toning is not considered natural or as desirable by the vast majority collectors who know this. The TPGs certainly weren't forthcoming in sharing this little secret, and before this entire thing blew up on these forums, neither were the recognized experts in these coins. Curiously enough they said nothing at all about it, and sold these coins for huge premiums to their value prior to conservation. While many buyers -- to include YOU before this little thread, and me before I learned on these forums before you -- had no idea. To me, that's deception -- a "dirty little secret" if you will -- and it's wrong any way you cut it, at least to me.

 

In fact, after doing my own tests and observing the results, for which I present above, I am indeed contradicting the old wives tale that MS70 causes blue-violet-red toning on copper. Every single photo above, every single before and after elsewhere, shows that brown patina was removed, free copper surfaces are not affected, and what is underneath is revealed.

 

I agree with every word, except "indeed" and "causes". First, you have not proven anything outside a PH and fingernail test. Second, you have shown precisely what I suggested in my very first words to you ( http://boards.collectors-society.com/ubbthreads.php?ubb=showflat&Number=4480015&fpart=1 ):

 

"The coin posted by the OP looks to me to be a MS-70ed Randall Hoard ... coin with some surface issues that likely looked much worse before it was improved."

 

"IMO, 64 is the right grade. Surfaces look clean enough for a 65, but the streaky nature of the obverse is a negative in the market. There is also some question as to the originality (or market-acceptability, if you will) of MS-70ed copper. Frankly, I'm a bit surprised to read it's in PCGS slab -- they view these coins, particularly recently, with a suspicious eye."

 

Ever since those words, you have attacked me and put words in my mouth -- all because I told you the truth as I saw it and you were ignorant that a dip in MS-70 led to that toning.

 

But that's OK, I'm a big boy, and I can take it.

 

All of the above said, and in fairness, you have shown something that I didn't believe was possible -- that what causes the blue toning may have been there the entire time. It is important to acknowledge this, and your contribution to enlightening me to this. I certainly didn't believe this was possible before our back and forth -- I have dismissed it on face value more than once -- and for that I owe you my thanks.

 

 

See for example this set of images by robec who I have great respect for, but disagree with him if he feels that MS70 did more than remove patina. What I note about removal, copper surfaces, and toning clearly is supported by these images;

 

Robec's images of the 1914 lincoln, down the page

 

 

Lastly, you failed to address my first four questions. No need to address all of them, as I can infer your answers from the ones you provided above. However, I would really like an answer to this one:

 

"Question #4: Now, based on your own direct experience with the substance, do you think your Randall Hoard coin was MS70ed?"

 

Haven't a clue, I believe the blue toning to be authentic given my results, clearly, some type of conservation agent has been applied to remove dirt, possibly patina, etc. If not MS70 that won't remove CuS sulfide, it may be that the old EAC way of doing it - xylol followed by blue ribbon was applied to remove grime, won't stop me from loving this large cent that is for sure

 

Thank you for being honest about admitting the conservation. That's a start! However, I think you have a bit more than "a clue" about if your coin's appearance was the result of a dip in something like MS-70.

 

Getting past that, if you will experiment with Xylol (which doesn't dissolve patina) and blue ribbon (which removes blue color, try it on your experiments) you will know that doesn't cause the change in coins like your own and if it did it would cancel the toning.

 

Just curious....Mike

 

p.s. Getting past the scariness that it is that delicate to begin with, I found it fascinating that the blue toning scratched off. That wasn't something I had heard of, tried, or even thought to have tried.

 

I explained it in the above post don't know what else I can do, so I recommend you read 'Manual of Mineral Science', Hurlbut and Klein, It is in its 23rd edition, originally published by Dana as Manual of Mineralogy back in the day. It will give you information about the Mohs hardness scale and how to apply it as I described in the previous post. I used the 19th edition, published in 1977 for this work. Hasn't changed much since then, but plenty more books to sell for mineralogy classes that are taught in just about every university out there. Toning on surfaces of coins is usually only a few microns thick at best, CuS is softer than a fingernail, oxides are not, copper is harder than a fingernail, the prediction that I tested is thus a fingernail should rub off toning if it is CuS, exposing clean copper underneath, oxide should not rub off with the fingernail. Go try to scratch off brown (if oxide) patina with your fingernail, does not work well, now try it on any coin with very thin sulfide on top of metal, it will work if it is CuS. Simple hardness test used to identify the materials in question. Having said that, you can find images all over the web of blue-violet-red toning that was likely 'lightly scratched/rubbed' off by something that did not harm the underlying surfaces after the coin was toned, making streaks or even less/untoned areas engulfed by the original tone. This is what is expected when the tone is soft like covellite.

 

You can get it here:

 

Hurlbut and Klein

 

I wasn't questioning you, I was simply saying it was neat! But thanks for the link to that book, I have ordered it too.

 

Finally, I will repeat a question/comment from a previous post again - why would NCS not tell NGC and possibly PCGS to stop slabbing with grades toned copper like this if it was AT and produced by a chemical? Maybe I am truly naive, but they must have come to the conclusion, doing their own experiments, that such coins are NT. Otherwise the implication is huge and probably this thread will be removed and I will be banned from these boards for even suggesting this. 'Market Grading' can go only so far, if what some claim, which I refute here, is that MS70 tones copper then a serious day of reckoning will be coming soon, amen.

 

The only issue I take with this is that you are confused that PCGS and NGC decide if a coin is NT or AT. Heck, the PNG can't even define the term! The TPGs decide if a coin is MA or not MA (i.e. market acceptable or not). They have no way of telling if a coin is natural or artificial in any authoritative way. They express their opinion on if the coin is acceptable to the market or not. I fear these numismatic truths are still lost on you based on your response above.

 

Also, i wouldn't worry to much about what you've said here. I've said much worse and I'm still around.

 

I love this copper with tiger stripes and NT and because it was the impetus for this study, I post it here again:

 

 

In the end, that's all that matters!

[Hard Times]

MikeinFl, okay you don't have an agenda, I am good with that, but seriously, I linked your post, it is easy to interpret what I did from your words. No worries I retract my insinuation.

 

The reason blue ribbon 'removes blue color' is the very same reason why oils do. They are coating the surface and changing how light is reflected from it, if you remove the oil or the blue ribbon, you will see that the color, if NT, will be revealed again. For example, the top images are my before and after (left and right) of the 2004D lincoln conserved with MS70 posted above. Below this, are images following MikeinFl suggestion that Blue Ribbon removes the blue tone. The top left image is after adding Blue Ribbon to the surface, the blue tone is missing in this image. However, if you angle the coin toward the light, you begin to see it is still there, this is the bottom left image. You also see how greasy the surface becomes with a Blue Ribbon layer. In hand, I can attest that blue-violet-red tone is still there when reflected in the light at just the right angle (hard to get it perfect for imaging). That demonstrates that all you have done is change the optical properties of the surface that is then picked up in the images. The top right image is after trying to remove the Blue Ribbon with soap and Xylol. Still not like it was prior to Blue Ribbon addition in the images, but blue-violet-red tone is beginning to show again in the image, especially with the bottom right image where it is again angled toward the light. When viewed in the right angle under the light, one can observe that nothing has changed, the toning is the same. All one has done is change the optical properties by adding stuff to the surface.

 

Okay you say, prove it. So the bottom image is when I re-applied MS70 in an effort to remove all of the Blue Ribbon and Xylol applied to test the optical property theory. Now we are back to being able to image almost the same as the coin was before applying the Blue Ribbon. I don't see any 'added' toning, but just that the toning can be better imaged after removal of the stuff on the surface and attempting to get the optical properties back to the same for imaging with removal of Blue Ribbon. What I did notice however, are the surfaces are becoming more abraded by lightly rolling several Q-tips over the surface that were saturated in the various concoctions. This is something Jerry Bobbe warned of in the CTCC journal, that this EAC 'doctoring' method of applying concoctions with q-tips results in fine hairlines in an uncirculated copper and forever damages it.

 

So what can we conclude from all of this? Blue Ribbon does not remove blue toning, it just changes the optical properties of the surface of a copper so that it is hard to get an image of the toning underlying the layer of Blue Ribbon added. Re-applying MS70 mostly took off the Blue Ribbon, and imaging the toning is easier.

 

My recommendation? Don't do this at home. If for any reason you want to 'conserve' a copper, send it to NCS. They have the best techniques and know how to conserve copper without any detrimental effects. Again, the choice is yours whether you prefer coppers where MS70 or another solution was applied to remove brown patina and reveal the underlying toning, or whether you prefer copper with more original surfaces. This debate on what is proper conservation will go on and on. Interestingly in the world of silver, I think less un-messed with specimens with more original toning are going for a premium versus acid dipped coins with blast white surfaces, at least in some series. Same might be said for MS70 conserved copper?

 

 

 

[Hard Times]

Here's my question concerning your 1817 coin, why only a 64 grade? Is it because of the color? I think it is a very strong strike looking at the pics, but, again many say you cannot give a accurate grade by a picture.. George

 

HI Yaha,

Apparently, the tiger stripes on the obverse may be considered negative eye appeal and take the coin down a point or two. This was Mark Feld's suggestion and he was a professional grader at one time. I actually think it adds eye appeal and makes this large cent distinctive, but eye appeal, like beauty, is in the eye of the beholder.

 

Best, HT

[Hard Times]

I can certainly understand your thoughts on the two images of the 1914 Lincoln Proofs. The way the post was written would even lead me to believe that I thought MS70 had something to do with the difference in appearance between the two images.

 

When I said

What do you suppose was used on this coin to turn it from the first image to the second?

I didn't mean for it to sound like my conclusion was that the resulting difference was due to MS70, I was actually asking what you thought had caused the change. It has to be some type of doctoring, although I like the before appearance better than the upgraded appearance.

 

Bob,

I am torn on which I like better, the before or after, but I think MS70 or another agent was used to remove the brown patina/oxide(?) and bring out the covellite toning on the surface. It is sure a stunning lincoln that is for sure. 'Removing' certain types of patina from coins is certainly not considered to leave a coin in its original state that is for sure, but we all know of hordes of examples of US coins that have been altered in such a way that they are still graded, slabbed, and considered acceptable (like almost all untoned silver from the 19th century sans Morgans). And I sure like some of my coppers with such vibrant toning, ir-respective of whether brown patina was removed or not. I guess each coin must be considered on a case by case basis, but it is good to know if something may have been done to alter original surfaces and what it specifically was that was done.

 

Best, HT

[MikeInFL]

HT,

 

Thank you for doing the legwork and posting the photos.

 

As you point out, I should not have said oils "removed" the toning but rather something like "minimizes" or "obscures". I think your experiments show that quite clearly, and they mimic the effects I saw when I did the same thing -- put oil on an MS-70 dipped coin and the blue color becomes far less blue in-hand.

 

Thank you for the correction....Mike

[MikeInFL]

Again, the choice is yours whether you prefer coppers where MS70 or another solution was applied to remove brown patina and reveal the underlying toning, or whether you prefer copper with more original surfaces. This debate on what is proper conservation will go on and on. Interestingly in the world of silver, I think less un-messed with specimens with more original toning are going for a premium versus acid dipped coins with blast white surfaces, at least in some series. Same might be said for MS70 conserved copper?

 

If I have understood you correctly (I was a bit thrown off by "less un-messed with" which seems to imply "more messed with" and doesn't agree with my take on the market), I think the above is very well said.

 

I also think that we are already there with respect to MS-70 and copper (i.e. the premium for these coins has evaporated in large part), but this is not as widely known or discussed as dipped silver, where dipped coins don't go for nearly as much as undipped and attractive ones do.

 

Take care...Mike

[Hard Times]

Mike I agree, with all you say in the last two posts.

 

Best, HT

[chinook]

Hard Times,

 

Thank you for your work in this thread. I would like to see you do more research on this topic using "original" mint state coins. Many of the coins you used are copper plated zinc modern coins, or or coins that had previously been messed with. Find a nice 1909 or 1910 lincoln cent in an original MS63 BN or RB--can be found for $15-20 and try your experiment. The amount of oxidation on the coin will effect the reaction of MS70 materially.

 

I am highly confident that your Randall Hoard large cent has been treated with MS-70, but still a decent coin with moderately attractive surfaces for the type.

[Hard Times]

Chinook, Thanks for the suggestions. I will do what you suggest and get back to this thread, when I can. I also want to to the elemental analyses of the surfaces that MikeinFl and I have gone back and forth on, that will definitely provide some very robust info. My summary so far, while I think is likely correct as I cannot see a viable alternative, should be tested with such data and MikeinFl is correct in suggesting this go further.

 

I am sure the NCS folks are laughing at this thread (Chris are you reading this I am going to hit you up about MS70 next time we cross paths at a show). They already have the info we are striving to obtain, no doubt.

 

I will start searching ebay for the coppers you suggest and let's see.

 

I am pretty sure also that MS70 or another detergent of similar properties was used on my Randall Hoard cent as well as many others out there, to remove the patina and grunge but since I did not do that myself, I can't say this is 100% certain. There are so many 'cleaning' agents out there, who knows. I still like it though, but now that I am armed with more information, will take this into account when considering future acquisitions.

 

Side note - George Takei (Mr. Sulu) is on CNN right now talking about the Japan Crisis, and he is not in his Star Trek uniform. Gotta say, he is looking well for his age, especially when compared to Mr. Kirk.

 

Best, HT

[MikeInFL]

Are you ready to complete the experiments? Standing by....Mike

[Hard Times]

HI Mike,

Thanks, not yet but want to, overwhelmed at work, I need to get access to an SEM for no cost, am working on that, I want to do XRD as well....

 

Best, HT

[MikeInFL]

Thanks for the update.

[Hard Times]

update.... The question from James EarlyUS about the gmarguli experiments using MS70 cleaner in a now defunct thread ATS inspired me to show an updated image here. If you read through above, you will see the experiments I did on copper coins using MS70. My conclusion is that you strip off patina and what lies underneath is what you get. I still believe in most cases that is what is occurring when MS70 is applied to copper coins. However, here is an interesting development. As noted above, I had an 1854 half cent I obtained from an insufficiently_thoughtful_person on ebay that was harshly cleaned (and not disclosed) a few years ago, that I applied MS70 to. As the images before and after above indicate, the half cent turned that characteristic blue of MS70 fame after application. None of the other examples I used, as shown in the images above, had this same pervasive blue sheen. Now it has been 6 months. All of the copper I used in the experiments have been enclosed in an unused 'Shoe Mitt' soft cloth that came from some hotel. Since the experiment all of the copper imaged above look exactly like they did when the 'after' images were taken with the exception of the 1854 half cent. It, on the other hand, has 'turned'. All of the blue color is gone. One day I looked at these a couple months ago and discovered this. See the images below. The 'before' is on the left, the 'after' is in the center, and the 'today' or 'turned' image is on the right. Not only did the blue sheen go away, but the coin became more lustrous. That is shown in the second set of images below, where the right hand image shows the half cent tilted in the light to better image the surface luster.

 

So what does all this mean? Heck I don't know. But for those who do not want doctored coins where MS70 was applied, this poses an issue because depending on how the copper is stored after application, much of the signature blue can go away and one might not be able to identify the copper as previously having had MS70 applied. This especially poses a problem for those who want shiny uncriculated copper - how does one tell if they are doctored? My take on MS70 is still mostly that is removes patina, but clearly something on the surface can be changed to that blue color, but then it appears to be ephemeral. So the question then is, will copper with this blue sheen from MS70 'turn' back over time when sitting in a slab and essentially minimized to ambient air? Or was there something in the shoe mitt cloth that somehow catalyzed a reaction to remove whatever the blue is on the half cent?

 

Thoughts? Best, HT

 

 

 

[Chris1976]

Wonderful post HT. I am wondering though and I'd like to hear your opinion as well, could it be possible that the blue that you had seen on the one coin may be due to the MS70 reacting with something else that had been applied long ago? It may be interesting to take a couple of coins that you really do not care about and let each one soak in various solutions for a couple days that are commonly used in attempts to conserve a less than appealing coin such as Acetone, common Jewerly cleaner, etc.

 

My thoughts are that if this is what happening (reactions to chemicals deep within the pores) that we may be able to determine what the coin had been treated with in the past simply by looking at the different color variations after an application of MS70.

 

-Chris#2

[DieClash]

MS-70 on a Morgan $1

 

 

 

[No+4Me]

fascinating thread, I had not seen it before.