@MercuryFB said:
Everyone, Thanks so much for your feedback. I will probably just keep it because to me it looks great; however, I don't think I will buy anymore graded or raw toned coins. I just looked at a couple toned graded coins on PCGS website first 2 pictures below and the last 2 pictures are PCGS Tone graded MS64 coins that are for sell. To me some of them look similar to mine and a couple look fake as hell to me. They all have purple color in them and a couple look like they have spots. To me they all look artificially toned yet PCGS graded all of these as Naturally toned. It cost too much to take chances. Thanks again!
Agree with TomB - Do what you got to do.
If however you still have a curiosity or other about toning, then this web page has some information. This link opens in the middle of the page at the NT / AT section.
@silviosi said: How to tell if coin is artificially toned?
Perform SEM-EDX (~2500 to 3000$) and you will find. The rest is relative. Many factors can affect the color spectrum development.
You know a lot more about coins than I do. Will you please explain this post. What EXACTLY will you find with this test that will indicate a coin is natural or AT. Thanks in advance.>
PCI "MS65"? What a joke! Must be one of their later gold holders. The coin was clearly toned to cover the cleaning and other prior damage/impairment. Sometimes you can tell at with mismatched front and back. Clearly the grading services have incisive criteria beyond just the typical "market acceptable".
Here's an example of a Bust half dime that was likely at, the dealer called the obverse AU58 and reverse MS64, I sent it to ICG that called it AU55 details, cleaned:
@MercuryFB, your subject has clearly inspired some hearty discussion! I won't weigh in on the "Artificial" vs "Natural" toning question, as it's a topic that's been (and continues to be) discussed broadly. But I'm a half dime guy, and I can attribute your coin for ya, if that's of any use! You have an 1830 LM-4.2 (R2) there. It's identifiable as an LM-4.x marriage because it pairs 1830 Obverse 2 with Reverse J. "LM" comes from the authors of the book Federal Half Dimes 1792-1837, Russ Logan and John McCloskey.
The book describes Obverse 2 as "(Star) S5, S6, &S7 not rotated and equally spaced." You can handily spot it when it's progressed to have the die crack from the rim, thru S1, and into the field.
Reverse J is described as "RI (in AMERICA) apart." Of course, there are other pickup points, including the start and end positions of the scroll, and the relationship of the second S in STATES to the S in PLURIBUS.
Reverse J was kinda like Elizabeth Taylor, in that she remarried frequently. In fact, Rev J's first use was in minting 1830 LM-4.1 (the .1 signifying the first of multiple unions of those two dies). Then Rev J was used in 1830 LM-5, 1829 LM-16.1, 1829 LM-17, 1829 LM-16.2, and FINALLY returning to the original 1830 Obv 2 to mint 1830 LM-4.2. (You see that some marriages like 1830 LM-5 didn't have remarriages, while others like 1829 LM-16.x did.)
BTW, I state conclusively that you have an LM-4.2 because it's during the minting of LM-4.2 that that the little chip in the upper loop of S2 forms. That will never be seen in LM-4.1 or any of those intermediate uses of the die. Other points of interest include the die chips in the N and M, and the clashes on the reverse over the eagle and the clash of the shield on Liberty's face.
It's a pretty coin, I will say! At R2, it's not a rare remarriage. Sometimes NGC is a little more amenable to straight-grading colorful coins that the competition is... but no guarantees there.
The designations "artificial" and "natural" are largely meaningless when it comes to chemical processes that are identical. Consider the following scenarios:
Scenario 1: Grandma back in the 1950s takes some nice shiny silver coins, carefully wraps them up in tissue paper (which she does not know is quite sulfur-rich), and puts them away in a drawer where they are forgotten about until she has passed away and her estate is being settled. The coins are now wonderfully toned.
Scenario 2: A Coin Collector in the 1990s takes some nice shiny silver coins and carefully wraps them up in tissue paper that he knows fully well (either by subjective experience or by objective testing) is laced with sulfur compounds, hoping to get some nicely toned coins out of this process. He puts them away in a drawer for 5 years. The coins are now wonderfully toned.
Scenario 3: A Coin Doctor (not intending to reference any of the honourable members with actual doctorates on this board, of which I am not one) in the 2020s takes some nice shiny silver coins, and deliberately puts them in a "gas chamber" filled with hydrogen sulfide gas. He leaves them in there for a few minutes or a few hours, carefully controlling the amount and flow of the gas within the chamber to attain the desired effect. The coins are now wonderfully toned.
Everyone would agree that Grandma's coins are NT, since it happened "naturally", without the deliberate intent by Grandma to tone the coins. Everyone would also agree that the Doctor's coins are AT, since not only was it "done deliberately", but it was an alien, accelerated-chemistry environment that caused the toning. The Scenario 2 coins might be up for debate as to whether or not they are "artifical"; the process was identical to that of the "natural" in Scenario 1, but there was a deliberate intent to tone, and hence "artificial".
But chemicals can't read people's minds, they know nothing of human "intent". They're simply obeying the laws of chemistry and physics as they are exposed to each other, which are identical in all three of these scenarios. Unless the coins from these three processes physically look different, then there is no functional difference between them that could be determinable by science, because in all three scenarios, the chemistry is identical: Silver plus sulfur gives silver sulfide.
Yes, if the Coin Doctor chooses to use totally alien chemicals to create his artificial toning (like a layer of oil, or a dip in clorox bleach) this could easily be detected by pretty much any analytical test (XRF, NIR, even GC) since the chemistry is different. But for scenarios with identical chemistry, this axiom holds: "A difference that makes no difference is no difference".
All of which is why it's really all a debate about "market acceptable" versus "market-unacceptable" toning - which is all about the appearance of the coin, not the chemical history of it. The physical appearance is readily proven, the chemical history is not.
Waste no more time arguing what a good man should be. Be one. Roman emperor Marcus Aurelius, "Meditations"
"All of which is why it's really all a debate about "market acceptable" versus "market-unacceptable" toning - which is all about the appearance of the coin, not the chemical history of it. The physical appearance is readily proven, the chemical history is not."
Care to explain: "...if the Coin Doctor chooses to use totally alien chemicals to create his artificial toning (like a layer of oil, or a dip in clorox bleach) this could easily be detected by pretty much any analytical test (XRF, NIR, even GC) since the chemistry is different.
Is is as simple as bleach chemicals are not found on NT coins? What about Hydrogen Sulfide? Thanks.
@Married2Coins said:
Care to explain: "...if the Coin Doctor chooses to use totally alien chemicals to create his artificial toning (like a layer of oil, or a dip in clorox bleach) this could easily be detected by pretty much any analytical test (XRF, NIR, even GC) since the chemistry is different.
Is is as simple as bleach chemicals are not found on NT coins? What about Hydrogen Sulfide? Thanks.
Not quite. Regular toning on silver coins is essentially made of silver sulfide. But chlorine bleach will react with silver to form a thin layer of silver chloride. Silver chloride "toning" looks distinctly different to regular sulfide toning (often strongly blue), and of course is readily apparent by a surface analyser like XRF, as "natural" toning shouldn't contain silver chloride unless the coin has been in seawater for several centuries. Silver chloride toning also does not come off in e-z-est or other acidic tarnish removers - once it forms, it's there forever unless you physically scrape it off.
So, detecting a silver chloride "tone" on a modern non-shipwreck coin is concrete proof of coin doctoring. But not detecting it is not necessarily proof of "natural" or "non-accelerated" toning, since sulfide toning can occur both "naturally" and "artificially".
Hydrogen sulfide is a volatile gas; any that doesn't react with the silver will quickly dissipate in open air. The human nose is particularly sensitive to hydrogen sulfide - "rotten egg gas". So if the coin is placed on a tabletop in normal air until it doesn't smell eggy any more, then no scientific instrument would detect toning caused by exposure to hydrogen sulfide either.
Waste no more time arguing what a good man should be. Be one. Roman emperor Marcus Aurelius, "Meditations"
Wanted to share this Proof Morgan from the James Allaire Millhound Sale by Stack's Bowers held in March 2023.
Mr. Millhound died in 1911 and the coins were kept in the family for several generations until 2023. Great story.
@Married2Coins said:
Care to explain: "...if the Coin Doctor chooses to use totally alien chemicals to create his artificial toning (like a layer of oil, or a dip in clorox bleach) this could easily be detected by pretty much any analytical test (XRF, NIR, even GC) since the chemistry is different.
Is is as simple as bleach chemicals are not found on NT coins? What about Hydrogen Sulfide? Thanks.
Not quite. Regular toning on silver coins is essentially made of silver sulfide. But chlorine bleach will react with silver to form a thin layer of silver chloride. Silver chloride "toning" looks distinctly different to regular sulfide toning (often strongly blue), and of course is readily apparent by a surface analyser like XRF, as "natural" toning shouldn't contain silver chloride unless the coin has been in seawater for several centuries. Silver chloride toning also does not come off in e-z-est or other acidic tarnish removers - once it forms, it's there forever unless you physically scrape it off.
So, detecting a silver chloride "tone" on a modern non-shipwreck coin is concrete proof of coin doctoring. But not detecting it is not necessarily proof of "natural" or "non-accelerated" toning, since sulfide toning can occur both "naturally" and "artificially".
Hydrogen sulfide is a volatile gas; any that doesn't react with the silver will quickly dissipate in open air. The human nose is particularly sensitive to hydrogen sulfide - "rotten egg gas". So if the coin is placed on a tabletop in normal air until it doesn't smell eggy any more, then no scientific instrument would detect toning caused by exposure to hydrogen sulfide either.
Thank you for your answer. You ancient collectors put me to shame. Lots to learn here. I'd like to see what silver chloride looks like on a silver coin. I dipped a Peace dollar in bleach when I read about clorox and all it did was make the coin gray. I also made the mistake of soaking a coin in old MS-70 to try and remove some stuff on it and it turned mostly purple. I wonder what chemical that toning is?
@Married2Coins said:
I'd like to see what silver chloride looks like on a silver coin. I dipped a Peace dollar in bleach when I read about clorox and all it did was make the coin gray.
If it was chlorine-based bleach, then you've already seen it. Not all bleaches are chlorine-based; some "chlorine-free" bleaches use peroxide or other agents.
@Married2Coins said:
I also made the mistake of soaking a coin in old MS-70 to try and remove some stuff on it and it turned mostly purple. I wonder what chemical that toning is?
Here's the MSDS - the material safety data sheet - for MS70. Everyone who manufactures and sells a chemical product needs to supply an MSDS and make it available for emergency services to freely access, in case of fire, poisoning, industrial accident, etc: http://www.translinesupply.com/PDF/MDSSHEETS/MS707530.MSDS.pdf
The days of "secret formulas" with secret ingredients are over, due to legal reasons; everyone's allergic to something these days and public disclosure is mandatory. The "secret" now is in the concentrations of the various ingredients, as the MSDS does not need to disclose this.
So, what are these ingredients, and why are they in MS70?
2-butoxyethanol, also known as "ethylene glycol monobutyl ether", is a surfactant - reducing surface tension, allowing the solution to completely wet the coin and soak into any encrustations on the surface of a coin.
Potassium hydroxide is a strong alkali. An alkali is "the opposite of an acid" in terms of they usually react strongly with acids, and can be quite corrosive themselves; the word "caustic" is usually applied to strong alkalis. However, alkalis are usually less corrosive to raw metal than acids are. The potassium hydroxide is the main ingredient for attacking and removing verdigris and corrosion from the coin. It will also neutralize any unreacted sulfuric acid lurking in any PVC goo.
Sodium gluconate has several properties, the most important of which in MS70 is that it bonds with raw metal without fully dissolving it. One of the advertised benefits of MS70 is that it leaves a "protective coating" behind on the coin, which can be washed off with acetone if it's not desired; this is the chemical that makes that coating.
"Sulfonated sodium salts" is imprecise; the CAS code 147732-60-3 comes up as sodium hexyldiphenyl ether sulfonate. I'm pretty sure the function of this chemical is as a detergent, so its purpose is to dissolve any oil and grease; it would also target PVC goo.
I love the euphemism "inert material"; CAS# 7732-18-5 is more commonly known as "water".
So, "old MS70" will have all of this, as well as whatever the MS70 would have dissolved off off previous coins - metal salts, oils, etc. I'm not sure which is more likely to cause your purple toning. It depends on how long it was "soaking"; MS70 is designed for quick on-and-off application and isn't really intended for long soaks. All of the chemicals in it, ought to do their job quite quickly. The detergent is sulfur-based, so I suspect it would cause toning if soaked for long periods or not washed off properly.
Waste no more time arguing what a good man should be. Be one. Roman emperor Marcus Aurelius, "Meditations"
@coastaljerseyguy said:
MS70 shouldn't turn silver coins purple, at least not for when I tried.
LOL. Trust me it does under certain conditions which I shall not reveal. Actually, I left out shades of orange and blue also. I learned this by accident and l had to learn how to avoid/control the "certain conditions."
Yes, every time I used MS70 it was only on the coin for < 1 minute, gentle swipe with Qtip, then a thorough rinse. Haven't used in over 5 years and haven't seen any negative effects on my coins. Didn't use much as I still have 90% of a bottle bought 15 years ago. B&M owner recommended for cleaning up dirty coins, and to only use on MS silver. Purportedly does not remove toning.
Married2Coins said:
Will you please explain this post. What EXACTLY will you find with this test that will indicate a coin is natural or AT. Thanks in advance.
From the main applications of the SEM-EDX:
1. Characterisation of material structures
2. Assessment of reaction interfaces, service environment and degradation mechanisms
3. Characterization of surface defects, stains and residues on metals, glasses, ceramics and polymers
4. Measurement of the thickness of layered structures, metallised layers, oxide films, composite materials using cross sectional imaging
5. Particulate and contaminant analysis on and within materials.
SEM:
1. Rapid, high resolution imaging with identification of elements present
2. Spatially resolved quantitative EDX (EDA) analysis of user defined areas on sample surface
3. Characterization of particulates and defects
4. Examination of grain structure and segregation effects
5. Coating thickness measurement using cross sectional imaging of polished sections.
They are more characteristics of this but I will not go in details. Because this it is an electron microprobe at about 50000x allow sub micron-scale features you to see, it easy to determine for example if the tonning was natural or artificial. Any artificial tonning will change the molecular structure in an incentive way. Then recognising the composition of this micro film could be determinate clear if was develop naturaly or artificialy.
EX: with electron microprobe we find many spectrum color of tonning in coins with different elements combinated with high % of iodine (I2) or potassium iodide (I-) which naturally could not be posible.
I saw a clad that has nice subtle colors on eBay. I figured that it might be real. I went to the seller’s offers and admired his scores of toned modern clads. Not a science there, though.
Comments
Agree with TomB - Do what you got to do.
If however you still have a curiosity or other about toning, then this web page has some information. This link opens in the middle of the page at the NT / AT section.
http://www.jhonecash.com/coins/tonedmorgans.asp#ntvsat
https://youtube.com/watch?v=_KWVk0XeB9o - Ruby Starr (from 'Go Jim Dandy') Piece Of My Heart
.
https://youtube.com/watch?v=D0FPxuQv2ns - Ruby Starr (from 'Go Jim Dandy') Maybe I'm Amazed
RLJ 1958 - 2023
I'm still waiting.
PCI "MS65"? What a joke! Must be one of their later gold holders. The coin was clearly toned to cover the cleaning and other prior damage/impairment. Sometimes you can tell at with mismatched front and back. Clearly the grading services have incisive criteria beyond just the typical "market acceptable".
Here's an example of a Bust half dime that was likely at, the dealer called the obverse AU58 and reverse MS64, I sent it to ICG that called it AU55 details, cleaned:
Here's an example of real toning. I hope this helps out.
Student of numismatics and collector of Morgan dollars
Successful BST transactions with: Namvet Justindan Mattniss RWW olah_in_MA
Dantheman984 Toyz4geo SurfinxHI greencopper RWW bigjpst bretsan MWallace logger7
Parts of this thread were interesting and educational and other parts were...
10-4,
My Instagram picturesErik
My registry sets
@MercuryFB, your subject has clearly inspired some hearty discussion! I won't weigh in on the "Artificial" vs "Natural" toning question, as it's a topic that's been (and continues to be) discussed broadly. But I'm a half dime guy, and I can attribute your coin for ya, if that's of any use! You have an 1830 LM-4.2 (R2) there. It's identifiable as an LM-4.x marriage because it pairs 1830 Obverse 2 with Reverse J. "LM" comes from the authors of the book Federal Half Dimes 1792-1837, Russ Logan and John McCloskey.
The book describes Obverse 2 as "(Star) S5, S6, &S7 not rotated and equally spaced." You can handily spot it when it's progressed to have the die crack from the rim, thru S1, and into the field.
Reverse J is described as "RI (in AMERICA) apart." Of course, there are other pickup points, including the start and end positions of the scroll, and the relationship of the second S in STATES to the S in PLURIBUS.
Reverse J was kinda like Elizabeth Taylor, in that she remarried frequently. In fact, Rev J's first use was in minting 1830 LM-4.1 (the .1 signifying the first of multiple unions of those two dies). Then Rev J was used in 1830 LM-5, 1829 LM-16.1, 1829 LM-17, 1829 LM-16.2, and FINALLY returning to the original 1830 Obv 2 to mint 1830 LM-4.2. (You see that some marriages like 1830 LM-5 didn't have remarriages, while others like 1829 LM-16.x did.)
BTW, I state conclusively that you have an LM-4.2 because it's during the minting of LM-4.2 that that the little chip in the upper loop of S2 forms. That will never be seen in LM-4.1 or any of those intermediate uses of the die. Other points of interest include the die chips in the N and M, and the clashes on the reverse over the eagle and the clash of the shield on Liberty's face.
It's a pretty coin, I will say! At R2, it's not a rare remarriage. Sometimes NGC is a little more amenable to straight-grading colorful coins that the competition is... but no guarantees there.
New website: Groovycoins.com Capped Bust Half Dime registry set: Bikergeek CBHD LM Set
The designations "artificial" and "natural" are largely meaningless when it comes to chemical processes that are identical. Consider the following scenarios:
Scenario 1: Grandma back in the 1950s takes some nice shiny silver coins, carefully wraps them up in tissue paper (which she does not know is quite sulfur-rich), and puts them away in a drawer where they are forgotten about until she has passed away and her estate is being settled. The coins are now wonderfully toned.
Scenario 2: A Coin Collector in the 1990s takes some nice shiny silver coins and carefully wraps them up in tissue paper that he knows fully well (either by subjective experience or by objective testing) is laced with sulfur compounds, hoping to get some nicely toned coins out of this process. He puts them away in a drawer for 5 years. The coins are now wonderfully toned.
Scenario 3: A Coin Doctor (not intending to reference any of the honourable members with actual doctorates on this board, of which I am not one) in the 2020s takes some nice shiny silver coins, and deliberately puts them in a "gas chamber" filled with hydrogen sulfide gas. He leaves them in there for a few minutes or a few hours, carefully controlling the amount and flow of the gas within the chamber to attain the desired effect. The coins are now wonderfully toned.
Everyone would agree that Grandma's coins are NT, since it happened "naturally", without the deliberate intent by Grandma to tone the coins. Everyone would also agree that the Doctor's coins are AT, since not only was it "done deliberately", but it was an alien, accelerated-chemistry environment that caused the toning. The Scenario 2 coins might be up for debate as to whether or not they are "artifical"; the process was identical to that of the "natural" in Scenario 1, but there was a deliberate intent to tone, and hence "artificial".
But chemicals can't read people's minds, they know nothing of human "intent". They're simply obeying the laws of chemistry and physics as they are exposed to each other, which are identical in all three of these scenarios. Unless the coins from these three processes physically look different, then there is no functional difference between them that could be determinable by science, because in all three scenarios, the chemistry is identical: Silver plus sulfur gives silver sulfide.
Yes, if the Coin Doctor chooses to use totally alien chemicals to create his artificial toning (like a layer of oil, or a dip in clorox bleach) this could easily be detected by pretty much any analytical test (XRF, NIR, even GC) since the chemistry is different. But for scenarios with identical chemistry, this axiom holds: "A difference that makes no difference is no difference".
All of which is why it's really all a debate about "market acceptable" versus "market-unacceptable" toning - which is all about the appearance of the coin, not the chemical history of it. The physical appearance is readily proven, the chemical history is not.
Roman emperor Marcus Aurelius, "Meditations"
Apparently I have been awarded one DPOTD.
I vote best answer!
"All of which is why it's really all a debate about "market acceptable" versus "market-unacceptable" toning - which is all about the appearance of the coin, not the chemical history of it. The physical appearance is readily proven, the chemical history is not."
Care to explain: "...if the Coin Doctor chooses to use totally alien chemicals to create his artificial toning (like a layer of oil, or a dip in clorox bleach) this could easily be detected by pretty much any analytical test (XRF, NIR, even GC) since the chemistry is different.
Is is as simple as bleach chemicals are not found on NT coins? What about Hydrogen Sulfide? Thanks.
Not quite. Regular toning on silver coins is essentially made of silver sulfide. But chlorine bleach will react with silver to form a thin layer of silver chloride. Silver chloride "toning" looks distinctly different to regular sulfide toning (often strongly blue), and of course is readily apparent by a surface analyser like XRF, as "natural" toning shouldn't contain silver chloride unless the coin has been in seawater for several centuries. Silver chloride toning also does not come off in e-z-est or other acidic tarnish removers - once it forms, it's there forever unless you physically scrape it off.
So, detecting a silver chloride "tone" on a modern non-shipwreck coin is concrete proof of coin doctoring. But not detecting it is not necessarily proof of "natural" or "non-accelerated" toning, since sulfide toning can occur both "naturally" and "artificially".
Hydrogen sulfide is a volatile gas; any that doesn't react with the silver will quickly dissipate in open air. The human nose is particularly sensitive to hydrogen sulfide - "rotten egg gas". So if the coin is placed on a tabletop in normal air until it doesn't smell eggy any more, then no scientific instrument would detect toning caused by exposure to hydrogen sulfide either.
Roman emperor Marcus Aurelius, "Meditations"
Apparently I have been awarded one DPOTD.
Wanted to share this Proof Morgan from the James Allaire Millhound Sale by Stack's Bowers held in March 2023.
Mr. Millhound died in 1911 and the coins were kept in the family for several generations until 2023. Great story.
Thank you for your answer. You ancient collectors put me to shame. Lots to learn here. I'd like to see what silver chloride looks like on a silver coin. I dipped a Peace dollar in bleach when I read about clorox and all it did was make the coin gray. I also made the mistake of soaking a coin in old MS-70 to try and remove some stuff on it and it turned mostly purple. I wonder what chemical that toning is?
MS70 shouldn't turn silver coins purple, at least not for when I tried.
If it was chlorine-based bleach, then you've already seen it.
Not all bleaches are chlorine-based; some "chlorine-free" bleaches use peroxide or other agents.
Here's the MSDS - the material safety data sheet - for MS70. Everyone who manufactures and sells a chemical product needs to supply an MSDS and make it available for emergency services to freely access, in case of fire, poisoning, industrial accident, etc: http://www.translinesupply.com/PDF/MDSSHEETS/MS707530.MSDS.pdf
The days of "secret formulas" with secret ingredients are over, due to legal reasons; everyone's allergic to something these days and public disclosure is mandatory. The "secret" now is in the concentrations of the various ingredients, as the MSDS does not need to disclose this.
So, what are these ingredients, and why are they in MS70?
2-butoxyethanol, also known as "ethylene glycol monobutyl ether", is a surfactant - reducing surface tension, allowing the solution to completely wet the coin and soak into any encrustations on the surface of a coin.
Potassium hydroxide is a strong alkali. An alkali is "the opposite of an acid" in terms of they usually react strongly with acids, and can be quite corrosive themselves; the word "caustic" is usually applied to strong alkalis. However, alkalis are usually less corrosive to raw metal than acids are. The potassium hydroxide is the main ingredient for attacking and removing verdigris and corrosion from the coin. It will also neutralize any unreacted sulfuric acid lurking in any PVC goo.
Sodium gluconate has several properties, the most important of which in MS70 is that it bonds with raw metal without fully dissolving it. One of the advertised benefits of MS70 is that it leaves a "protective coating" behind on the coin, which can be washed off with acetone if it's not desired; this is the chemical that makes that coating.
"Sulfonated sodium salts" is imprecise; the CAS code 147732-60-3 comes up as sodium hexyldiphenyl ether sulfonate. I'm pretty sure the function of this chemical is as a detergent, so its purpose is to dissolve any oil and grease; it would also target PVC goo.
I love the euphemism "inert material"; CAS# 7732-18-5 is more commonly known as "water".
So, "old MS70" will have all of this, as well as whatever the MS70 would have dissolved off off previous coins - metal salts, oils, etc. I'm not sure which is more likely to cause your purple toning. It depends on how long it was "soaking"; MS70 is designed for quick on-and-off application and isn't really intended for long soaks. All of the chemicals in it, ought to do their job quite quickly. The detergent is sulfur-based, so I suspect it would cause toning if soaked for long periods or not washed off properly.
Roman emperor Marcus Aurelius, "Meditations"
Apparently I have been awarded one DPOTD.
LOL. Trust me it does under certain conditions which I shall not reveal. Actually, I left out shades of orange and blue also. I learned this by accident and l had to learn how to avoid/control the "certain conditions."
One thing that's for certain is that every single toned silver eagle is questionable... at least that's what I hear
Yes, every time I used MS70 it was only on the coin for < 1 minute, gentle swipe with Qtip, then a thorough rinse. Haven't used in over 5 years and haven't seen any negative effects on my coins. Didn't use much as I still have 90% of a bottle bought 15 years ago. B&M owner recommended for cleaning up dirty coins, and to only use on MS silver. Purportedly does not remove toning.
In the early days of the American Silver Eagles, it was easy to tell. They were rainbow toned, and in PCGS slabs. Sad, but absolutely true.....
you lost me at "electron microprobe"
Then stop buying, they can't even define it.
One too many months in a taco bell napkin.
I saw a clad that has nice subtle colors on eBay. I figured that it might be real. I went to the seller’s offers and admired his scores of toned modern clads. Not a science there, though.