@Mark said: @spacehayduke Re the coins you photographed: After 2014, did you by chance use MS70 on them again? I think it would be interesting to see if the coloring was repeatable.
If true (I have no reason to doubt you), this is profoundly disturbing. It is a grading service's job to detect AT. When some collectors expressed dismay with the copper color guarantee change as applied to older coins either Hall or Willis (I forget which) posted that it applied only to color changes that didn't change the grade. If a coin is AT then the grade necessarily changes from a straight grade to a details grade.
Re the above, no. As I understand it, if you buy a RD Copper slabbed post 2009 or 2010, or cannot show proof you owned such coin before the restriction re RD Copper took place, caveat emptor if the color changes.
"Vou invadir o Nordeste, "Seu cabra da peste, "Sou Mangueira......."
@Mark said: @spacehayduke Re the coins you photographed: After 2014, did you by chance use MS70 on them again? I think it would be interesting to see if the coloring was repeatable.
Agreed
Good question, it is only one coin, front and back, and I will do so again when I get back home next week to see what happens.
@keets said:
spacehayduke, the point I have stressed is that the results obtained by one person(you in this case) aren't the results everyone gets. for that reason it is important for us all to accept that there is no absolute regarding the use of MS70. I suppose that since I don't show photographic "proof" that I can be discounted and not believed, but my experience is still valid. the results vary.
I would not disagree with that, but results should be repeatable by multiple people to be established as real. Coins can have all kinds of things on their surfaces, and I would guess that MS70 would react differently depending on what is on the surfaces. But blue toning like in the original post is clearly not an MS70 product, it is the out come of a reaction with copper over time to produce a thin film of product (toning) on the surface and embedded into the copper, not 'floating' on the copper, IMO. On my half cent, the blue floated on the copper and went away over time, revealing surfaces underneath with toning and areas stripped of patina. I really need to do some analytical work on this issue, wish I had the time and money for it......
I agree with @keets. From my experience with copper coins turning blue, it is a coin-by-coin reaction. I will add that I'm NEVER trying to do it on purpose and ALWAYS have changed the color back to the way it was (minus the impurities) when the conservation process is over.
@CircCam said:
Did someone say blue toned Indians?
I do wonder how they’d react to an acetone soak, but I’m not cracking them to find out. I’m in the camp that it can be natural and can also be artificially done.
@CircCam said:
Did someone say blue toned Indians?
I do wonder how they’d react to an acetone soak, but I’m not cracking them to find out. I’m in the camp that it can be natural and can also be artificially done.
All of these have been treated with MS70.
What characteristics lead you to that assertion out of curiosity? I’ve never bought a bottle of the stuff and tried myself on MS Indians so I’m always interested to hear what the tipoffs are from those who have. Thanks
@MFeld said:
There are a number of highly expert collectors, dealers and graders who are not "fools" and who don't believe that the MS70 issue is a myth or urban legend.
I would love to see their proof for the myth. Here is an example where I used MS70, changed the copper to blue. It did not keep, because it was a volatile component that over 3 years, volatilized into the atmosphere. So sure, if the right stuff is on the surfaces, MS70 will turn a copper coin blue, but it won't stay, don't confuse that with the toning in the OP, or have the highly expert collectors show they can generate such toning with MS70 and keep it there for many years. Proof is needed to keep the myth going.
There's some questionable science here.
Did you do this to ten coins or just one?
Volatile compounds tend not to be colored due to the way color emerges from molecular structure.
If the compound on the surface were "volatile", it also should have been possible to wash it away with either water or acetone. Did you try?
You can get a thin film effect from volatile compounds that leads to color (think oil in a puddle) but that would be due to improper cleaning of the coin after application of MS70.
If what you say is true, the effect should be repeatable with that coin, have you tried?
I have some English large cents around here that are blue from MS70 and have been for 15 years since I was playing around with them. I also have a bunch of Indian cents in my junk box that are blue/purple from an MS70 bath and have been for about 5 years. So, your result is not the norm, whatever might have been happening there.
@CircCam said:
Did someone say blue toned Indians?
I do wonder how they’d react to an acetone soak, but I’m not cracking them to find out. I’m in the camp that it can be natural and can also be artificially done.
All of these have been treated with MS70.
What characteristics lead you to that assertion out of curiosity? I’ve never bought a bottle of the stuff and tried myself on MS Indians so I’m always interested to hear what the tipoffs are from those who have. Thanks
Buy yourself a bottle and experiment. Tis better to learn to fish than be given a fish.
Unc coins work best. Try on some wheat cents first. You will soon learn to see the type of brown toning that best turns blue/purple. The "harder" the surfaces (and you will soon know what i mean) the more vibrant the toning.
@CircCam said:
Did someone say blue toned Indians?
I do wonder how they’d react to an acetone soak, but I’m not cracking them to find out. I’m in the camp that it can be natural and can also be artificially done.
All of these have been treated with MS70.
What characteristics lead you to that assertion out of curiosity? I’ve never bought a bottle of the stuff and tried myself on MS Indians so I’m always interested to hear what the tipoffs are from those who have. Thanks
Buy yourself a bottle and experiment. Tis better to learn to fish than be given a fish.
Unc coins work best. Try on some wheat cents first. You will soon learn to see the type of brown toning that best turns blue/purple. The "harder" the surfaces (and you will soon know what i mean) the more vibrant the toning.
Have fun.😀
It is indeed. Challenge accepted!
...how about these two? They are toned but have a much different vibe than the above coins I posted.
Both are in PCGS MS65BN holders, not that it matters much in regard to this topic... just giving an idea that the luster is there in hand.
Simply take a bunch of Lincoln cents out of pocket change, and send them through a wash cycle with detergent..
Observe the results with your own two eyes -- some will almost certainly become a certain tone of blue -- then please try to argue those coins are naturally toned.
Collector of Large Cents, US Type, and modern pocket change.
Treating random coins that are in circulation with MS70 cannot deliver definitive results as their existing surface condition can be widely variant. Instead, treat five or ten original RD pre 1958 PR cents with MS70 and see if any of them turn blue. I have done this, but with only two or three coins, so I do not consider this evidence of MS70 not imparting blue toning. I am reasonably sure that MS70, or acetone for that matter, just remove an overlying non toning layer that exists on the coin surface.
@OldIndianNutKase said:
Treating random coins that are in circulation with MS70 cannot deliver definitive results as their existing surface condition can be widely variant. Instead, treat five or ten original RD pre 1958 PR cents with MS70 and see if any of them turn blue. I have done this, but with only two or three coins, so I do not consider this evidence of MS70 not imparting blue toning. I am reasonably sure that MS70, or acetone for that matter, just remove an overlying non toning layer that exists on the coin surface.
OINK
From what I’ve read, I’d suggest treating RB and BN examples, not RD ones.
Mark Feld* of Heritage Auctions*Unless otherwise noted, my posts here represent my personal opinions.
From what I've seen with my own two eyes, Mark, you are correct. Nothing happens to red coins. The coin needs to have some skin for the blue to become apparent after layers of brown are chemically removed from the coin. The same thing happens from both MS-70 and regular laundry detergent, both of which I have experimented extensively with.
Collector of Large Cents, US Type, and modern pocket change.
@MFeld@keets "From what I’ve read, I’d suggest treating RB and BN examples, not RD ones."
The premise is that MS70 imparts the blue color on copper coins. If no color is imparted on a RD coin then that means that MS70 is not a coloring agent. Applying it to an BN or RB coin only proves that it can remove surface contaminants, but apparently not the underlying blue toning..
The premise is that MS70 imparts the blue color on copper coins. If no color is imparted on a RD coin then that means that MS70 is not a coloring agent. Applying it to an BN or RB coin only proves that it can remove surface contaminants, but apparently not the underlying blue toning..
OINK
If no color is imparted to a RD coin, it could mean there’s nothing on its surface with which the MS70 can react. And if the MS70 reacts with something on a BN or RB example, I don’t think that’s the same thing as exposing blue color which wasn’t apparent, previously.
Mark Feld* of Heritage Auctions*Unless otherwise noted, my posts here represent my personal opinions.
@OldIndianNutKase said:
Treating random coins that are in circulation with MS70 cannot deliver definitive results as their existing surface condition can be widely variant. Instead, treat five or ten original RD pre 1958 PR cents with MS70 and see if any of them turn blue. I have done this, but with only two or three coins, so I do not consider this evidence of MS70 not imparting blue toning. I am reasonably sure that MS70, or acetone for that matter, just remove an overlying non toning layer that exists on the coin surface.
OINK
They wont turn blue. The copper needs to be oxidized to react to the MS70.
@cohodk "They wont turn blue. The copper needs to be oxidized to react to the MS70."
You are correct that MS 70 will not have any effect on an original Cu RD coin. But your assumption that MS 70 reacts with copper oxide (s) needs validation from a basic chemical basis. MS70 is a base, not and acid, and it's reactivity is for the most part negligible if at all. But it will remove organic surface contaminants just like acetone.
Interestingly, I have a PR 1872 IHC that is RD but graded .91 Questionable Color. MS70 unfortunately did not turn it blue. It may live forever in the de-numismatized zone. Maybe someone turned it RD, but I can't turn it blue. MS70 is way over rated.
@erwindoc said:
I would like to see a half MS70 treated and half untreated coin!
I have done that too, and will post the results here in the near future. The advocates of MS70 turning copper blue won't like the result.......
Best, SH
I wouldn't say that at all. I appreciate empirical evidence and experimentation. The data are valued regardless of what conclusions we might draw from it. Also for whatever it is worth, I have never taken the position that all blue copper is MS70ed/ATed or natural. I have always taken the middle road. While blue copper likely naturally exists, I do think a number of examples on the market (particularly the electric blues and purples) are suspect. Of course reaction conditions also matter. For instance, Rick Snow has taken the position that acetone cannot tone copper coins and for many coins there is no effect; however, there are peer reviewed journal articles for conservators of artifacts suggesting a photo catalytic mechanism by which acetone could in fact tone copper under ambient conditions. I'll try to find it again.
@OldIndianNutKase said: @cohodk But your assumption that MS 70 reacts with copper oxide (s) needs validation from a basic chemical basis.
Lol. Just spend $30 and experiment yourself. Better yet spend $60 and find a nice brown (especially if it still had a little red) ms63ish IHC. I think there is even on on the BST what would turn a lovely purple similar to those previously posted in this thread.
Interestingly, I have a PR 1872 IHC that is RD but graded .91 Questionable Color. MS70 unfortunately did not turn it blue.
reread the posts above, you aren't paying attention or perhaps missed when it was stated clearly several times that based on the experiences of several members MS70 does not react with red coins to turn them blue.
Looking at the chemicals present in MS70, the key ingredient as regards color formation is potassium hydroxide. This strong base doesn't react with metallic sodium at room temperature. It will readily react with oxidized copper compounds (salts) on the coin. Copper hydroxide will be produced, which is a pale blue/green compound. Copper hydroxide is not particularly stable, and can decompose over time, resulting in a change or loss of the blue color.
The other compounds listed act as detergents to remove organics, etc. None of these would be involved in color formation.
Many copper salts are blue / green in color. Environmental exposure under the right conditions can allow formation of blue / green patina on copper. This is not uncommon.
@ADG said:
Looking at the chemicals present in MS70, the key ingredient as regards color formation is potassium hydroxide. This strong base doesn't react with metallic sodium at room temperature. It will readily react with oxidized copper compounds (salts) on the coin. Copper hydroxide will be produced, which is a pale blue/green compound. Copper hydroxide is not particularly stable, and can decompose over time, resulting in a change or loss of the blue color.
**The other compounds listed act as detergents to remove organics, etc. None of these would be involved in color formation. **
Many copper salts are blue / green in color. Environmental exposure under the right conditions can allow formation of blue / green patina on copper. This is not uncommon.
But what about the sulfonated sodium salts mentioned in the MSDS?
================== SECTIONI -PRODUCT IDENTIFICATION ===============PRODUCT DESCRIPTION:MS-70 Industrial Strength Coin BrightenerD.O.T. PROPER SHIPPING NAME: COMPOUND CLEANING LIQUID (POTASSIUM HYDROXIDE AND SODIUM GLUCONATE) 8, NA1760, II NFPA CODES: HEALTH -1 FLAMMABILITY -0 CORROSIVE -3 REACTIVITY -0======================= SECTION II -COMPONENTS =====================ETHANOL, 2-BUTOXY PEL: 25 PPM CAS #: 111-76-2 TLV: 25 PPM POTASSIUM HYDROXIDE, LIQUID PEL: NOT ESTABLISHED CAS #: 1310-58-3 TLV: NOT ESTABLISHED SODIUM GLUCONATE PEL: NOT ESTABLISHED CAS #: 527-07-1 TLV: NOT ESTABLISHED SULFONATED SODIUM SALTS PEL: NOT ESTABLISHED CAS #: 147732-60-3 TLV: NOT ESTABLISHED INERT MATERIAL PEL: NOT ESTABLISHED CAS #: 7732-18-5 TLV: NOT ESTABLISHED
@ADG said:
Looking at the chemicals present in MS70, the key ingredient as regards color formation is potassium hydroxide. This strong base doesn't react with metallic sodium at room temperature. It will readily react with oxidized copper compounds (salts) on the coin. Copper hydroxide will be produced, which is a pale blue/green compound. Copper hydroxide is not particularly stable, and can decompose over time, resulting in a change or loss of the blue color.
And exposure to acids could accelerate the decomposing.
Some refer to overgraded slabs as Coffins. I like to think of them as Happy Coins.
Any new information on this issue? Did any of the TPGs or other third parties do controlled experiments to get more clarity? This is the latest info I could find (this thread and the linked Shepherd article).
@MrEureka said:
I don’t know about MS70, but I’ve seen ammonia turn copper coins blue.
On another post I displayed some copper exposed to NH3 vapor which turned the sample blue, although not exactly Gem quality.
But at one time in our not too distant past, ammonia and water solution was a very common cleaning solution for residential and commercial purposes. My mother used ammonia for difficult cleaning jobs when I was growing up in the 1950's. The smell of the vapor was very noticeable in the house. I am sure that many colorfully toned coins were not solely due to sulfur bearing envelopes, but to airborne ammonia cleaning solutions as well.
Forgive me for resurrecting an old thread, but I found this discussion pretty interesting. A discussion came up with a fellow forum member about a wildly blue and purple toned proof IHC that was posted on instagram. I tried to search the archives to see what the consensus was and how perception may have changed over the years, and this was the most relevant thread I could find. How has the market perception changed, if at all, since this thread was made? Are neon purple and blue IHC's widely accepted by both TPG's and CAC? Has there been any additional information that has come to light in recent years?
I've posted this one before and although only Pf 65, in hand this is nearly cameo with a green/gold color that makes it one of a kind. It's a special coin to me !
@DeplorableDan said:
Forgive me for resurrecting an old thread, but I found this discussion pretty interesting. A discussion came up with a fellow forum member about a wildly blue and purple toned proof IHC that was posted on instagram. I tried to search the archives to see what the consensus was and how perception may have changed over the years, and this was the most relevant thread I could find. How has the market perception changed, if at all, since this thread was made? Are neon purple and blue IHC's widely accepted by both TPG's and CAC? Has there been any additional information that has come to light in recent years?
I’m not aware of generally changed perceptions or an end to the debate on this topic.
I think it’s fair to say that some blue/purple copper coins have acquired their color naturally and others haven’t.
Mark Feld* of Heritage Auctions*Unless otherwise noted, my posts here represent my personal opinions.
Here’s what I wrote a while back when I bought a blue Indian:
“Now, if you're as good as I know you are, you're probably all thinking two letters and two numbers: MS70. It comes together with blue Indians.
Here's my reply to that. I've read every thread I could find on the topic, and I've developed my own opinion. I'll try to detail it out here.
There are generally two stances on the topic:
1) MS70 only removes surface contamination, revealing natural blue color.
2) MS70 causes the blue color.
There are variations of these, but not many. The most common variation is similar to my stance here:
1) MS70 can cause a blue color, but not always. It must have a specific type of coin with the proper surface state to cause a blue color. The blue can also occur naturally, and this is seen frequently in untouched collections. Such an example is the Millholland Collection, where several blue Indian proofs and one 2c piece appear deep blue. The collection is quite literally the poster child for unmessed with original.
It is notable that every single Proof Indian in the Millholland Collection was partially blue, and every coin but two had at least one side majority blue.
In my opinion, I really don't care if this proof is a MS70 coin. Here's why:
1) Do I think I could tell the difference between a natural and MS70 coin? No.
2) Do I think PCGS/NGC could tell the difference? Nope.
3) What about CAC? Not them either.
4) Rick Snow and his Eagle Eye sticker that the forum almost unanimously said was better than CAC for this series and @winesteven wisely considers to be a qualifier for his exceptional Indian set? Probably not - but he also takes the stance that MS70 doesn't cause blue on Indians (he says it simply reveals it).
So if the foremost experts in this kind of grading can't tell, then we either have to throw out every blue proof original or not or just enjoy them for what they are. CAC threw out the whole bunch, and yet these proofs bring substantial premiums in the market, which clearly decides that these coins are indeed market acceptable, whether you or I like it.
I think we sometimes overestimate originality. There aren't many truly original coins out there. Consider the original thread that was here this week - not many of those were original. Given, the term "original" might have been misunderstood by a large chunk of posters .
There's also a chance this proof is entirely original - I'd have no idea how to tell for certain. NGC didn't have an issue with it. If you simply gave me this coin and told me nothing about MS70, I'd unhesitatingly call it original. The coin has a great "skin" to it, and the toning disappears to a rich brown unless it's in the light. It has some great elevation chromatics, and looks exactly like the proofs out of the Millholland Collection and Eliasberg sets. It's exactly what I'd expect for a coin our of one of the blue proof hoards of the early 1900s.
It's also exactly what I wanted with a Proof Indian. Great color, no annoying spots, and good deep mirrors with some orange peel. These things are dang near impossible to find nice these days, and I wasn't gonna settle.”
As a generalization, I believe Rick Snow is perfectly fine with many of the blue proof Indians. However, contrary to that, I also believe that JA at CAC is not comfortable stickering many blue proof Indians.
Steve
A day without fine wine and working on your coin collection is like a day without sunshine!!!
This is my favorite blue IHC proof which I bought from Rick Snow:
It does have his Photoseal sticker, which I feel is more credible than a green CAC bean. It is graded PR67BN.
BTW: I am in the camp who has tried to turn coins blue with MS70 and despite many attempts have had no success. I can turn them turquoise with NH3 however. Ammonia was a very common cleaning agent years ago and I suspect that it could have played a role with toning IHC proofs stored in paper envelopes.
As I stated 4 years ago in this thread, I believe 2/3 of the blue copper coins are AT and I can't tell the difference with most, so I stay away. Admittedly, part of this is that I am a RD and RB copper guy. Given that CAC hasn't beaned any of them also leads me to believe that the % is probably higher than I originally thought.
Having said that, I have a lot of respect for Rick Snow and I think OINKs coin has nice eye appeal but honestly I like the reverse color better than the obverse - that's just a personal preference.
Unfortunately, this doctoring bled into the matte proof Lincoln arena about 5 years ago, and several blue PR67BNs were "made" in a short period of time. You can look at Coinfacts and see that there is basically one blue 67BN for every year. Quite a coincidence that no PR67BNs had ever existed at PCGS for most of these dates then bam, neon blue all over the place..... JMHO
This is interesting in that I have used MS70 experimentally on US and GB copper and bronze and have many times gotten such results very similar to the 1885 above.
Love that Milled British (1830-1960) Well, just Love coins, period.
Comments
Agreed
Re the above, no. As I understand it, if you buy a RD Copper slabbed post 2009 or 2010, or cannot show proof you owned such coin before the restriction re RD Copper took place, caveat emptor if the color changes.
"Seu cabra da peste,
"Sou Mangueira......."
But Urban Legend, But Proskey, But Smith, But Eliasberg, but.....
....Tide.
Found the only coin in the original blog article that's no longer PCGS certified. It is now:
1885 Proof Indian Cent NGC PF-68BN
Here's the photo on the SIMCO site and the TrueView from the blog article:
I would like to see a half MS70 treated and half untreated coin!
Good question, it is only one coin, front and back, and I will do so again when I get back home next week to see what happens.
Best SH
I have done that too, and will post the results here in the near future. The advocates of MS70 turning copper blue won't like the result.......
Best, SH
Looks like it did the same thing as MS70, stripped off patina. I will try that experiment........
I would not disagree with that, but results should be repeatable by multiple people to be established as real. Coins can have all kinds of things on their surfaces, and I would guess that MS70 would react differently depending on what is on the surfaces. But blue toning like in the original post is clearly not an MS70 product, it is the out come of a reaction with copper over time to produce a thin film of product (toning) on the surface and embedded into the copper, not 'floating' on the copper, IMO. On my half cent, the blue floated on the copper and went away over time, revealing surfaces underneath with toning and areas stripped of patina. I really need to do some analytical work on this issue, wish I had the time and money for it......
Best, SH
I agree with @keets. From my experience with copper coins turning blue, it is a coin-by-coin reaction. I will add that I'm NEVER trying to do it on purpose and ALWAYS have changed the color back to the way it was (minus the impurities) when the conservation process is over.
Acetone will not remove the blue color.
Knowledge is the enemy of fear
The application of heat will cause clad coins to tone.
Knowledge is the enemy of fear
All of these have been treated with MS70.
Knowledge is the enemy of fear
What characteristics lead you to that assertion out of curiosity? I’ve never bought a bottle of the stuff and tried myself on MS Indians so I’m always interested to hear what the tipoffs are from those who have. Thanks
There's some questionable science here.
Did you do this to ten coins or just one?
Volatile compounds tend not to be colored due to the way color emerges from molecular structure.
If the compound on the surface were "volatile", it also should have been possible to wash it away with either water or acetone. Did you try?
You can get a thin film effect from volatile compounds that leads to color (think oil in a puddle) but that would be due to improper cleaning of the coin after application of MS70.
If what you say is true, the effect should be repeatable with that coin, have you tried?
I have some English large cents around here that are blue from MS70 and have been for 15 years since I was playing around with them. I also have a bunch of Indian cents in my junk box that are blue/purple from an MS70 bath and have been for about 5 years. So, your result is not the norm, whatever might have been happening there.
Buy yourself a bottle and experiment. Tis better to learn to fish than be given a fish.
Unc coins work best. Try on some wheat cents first. You will soon learn to see the type of brown toning that best turns blue/purple. The "harder" the surfaces (and you will soon know what i mean) the more vibrant the toning.
Have fun.😀
Knowledge is the enemy of fear
It is indeed. Challenge accepted!
...how about these two? They are toned but have a much different vibe than the above coins I posted.
Both are in PCGS MS65BN holders, not that it matters much in regard to this topic... just giving an idea that the luster is there in hand.
It is even easier to do that that...
Simply take a bunch of Lincoln cents out of pocket change, and send them through a wash cycle with detergent..
Observe the results with your own two eyes -- some will almost certainly become a certain tone of blue -- then please try to argue those coins are naturally toned.
Treating random coins that are in circulation with MS70 cannot deliver definitive results as their existing surface condition can be widely variant. Instead, treat five or ten original RD pre 1958 PR cents with MS70 and see if any of them turn blue. I have done this, but with only two or three coins, so I do not consider this evidence of MS70 not imparting blue toning. I am reasonably sure that MS70, or acetone for that matter, just remove an overlying non toning layer that exists on the coin surface.
OINK
From what I’ve read, I’d suggest treating RB and BN examples, not RD ones.
Mark Feld* of Heritage Auctions*Unless otherwise noted, my posts here represent my personal opinions.
From what I've seen with my own two eyes, Mark, you are correct. Nothing happens to red coins. The coin needs to have some skin for the blue to become apparent after layers of brown are chemically removed from the coin. The same thing happens from both MS-70 and regular laundry detergent, both of which I have experimented extensively with.
Is this changing colors anything like the magic felt pad?
MS70, before and after. Exact same lighting and camera setup for all photos, no color or brightness adjustments made to image.
treat five or ten original RD pre 1958 PR cents with MS70 and see if any of them turn blue.
try Brown coins.
@MFeld @keets "From what I’ve read, I’d suggest treating RB and BN examples, not RD ones."
The premise is that MS70 imparts the blue color on copper coins. If no color is imparted on a RD coin then that means that MS70 is not a coloring agent. Applying it to an BN or RB coin only proves that it can remove surface contaminants, but apparently not the underlying blue toning..
OINK
Applying it to an BN or RB coin only proves that it can remove surface contaminants, but apparently not the underlying blue toning.
no, I don't think it "only proves" that at all.
--- CuO and Cu2O.
If no color is imparted to a RD coin, it could mean there’s nothing on its surface with which the MS70 can react. And if the MS70 reacts with something on a BN or RB example, I don’t think that’s the same thing as exposing blue color which wasn’t apparent, previously.
Mark Feld* of Heritage Auctions*Unless otherwise noted, my posts here represent my personal opinions.
They wont turn blue. The copper needs to be oxidized to react to the MS70.
Knowledge is the enemy of fear
@cohodk "They wont turn blue. The copper needs to be oxidized to react to the MS70."
You are correct that MS 70 will not have any effect on an original Cu RD coin. But your assumption that MS 70 reacts with copper oxide (s) needs validation from a basic chemical basis. MS70 is a base, not and acid, and it's reactivity is for the most part negligible if at all. But it will remove organic surface contaminants just like acetone.
Interestingly, I have a PR 1872 IHC that is RD but graded .91 Questionable Color. MS70 unfortunately did not turn it blue. It may live forever in the de-numismatized zone. Maybe someone turned it RD, but I can't turn it blue. MS70 is way over rated.
OINK
I wouldn't say that at all. I appreciate empirical evidence and experimentation. The data are valued regardless of what conclusions we might draw from it. Also for whatever it is worth, I have never taken the position that all blue copper is MS70ed/ATed or natural. I have always taken the middle road. While blue copper likely naturally exists, I do think a number of examples on the market (particularly the electric blues and purples) are suspect. Of course reaction conditions also matter. For instance, Rick Snow has taken the position that acetone cannot tone copper coins and for many coins there is no effect; however, there are peer reviewed journal articles for conservators of artifacts suggesting a photo catalytic mechanism by which acetone could in fact tone copper under ambient conditions. I'll try to find it again.
Lol. Just spend $30 and experiment yourself. Better yet spend $60 and find a nice brown (especially if it still had a little red) ms63ish IHC. I think there is even on on the BST what would turn a lovely purple similar to those previously posted in this thread.
Knowledge is the enemy of fear
Interestingly, I have a PR 1872 IHC that is RD but graded .91 Questionable Color. MS70 unfortunately did not turn it blue.
reread the posts above, you aren't paying attention or perhaps missed when it was stated clearly several times that based on the experiences of several members MS70 does not react with red coins to turn them blue.
Looking at the chemicals present in MS70, the key ingredient as regards color formation is potassium hydroxide. This strong base doesn't react with metallic sodium at room temperature. It will readily react with oxidized copper compounds (salts) on the coin. Copper hydroxide will be produced, which is a pale blue/green compound. Copper hydroxide is not particularly stable, and can decompose over time, resulting in a change or loss of the blue color.
The other compounds listed act as detergents to remove organics, etc. None of these would be involved in color formation.
Many copper salts are blue / green in color. Environmental exposure under the right conditions can allow formation of blue / green patina on copper. This is not uncommon.
But what about the sulfonated sodium salts mentioned in the MSDS?
================== SECTIONI -PRODUCT IDENTIFICATION ===============PRODUCT DESCRIPTION:MS-70 Industrial Strength Coin BrightenerD.O.T. PROPER SHIPPING NAME: COMPOUND CLEANING LIQUID (POTASSIUM HYDROXIDE AND SODIUM GLUCONATE) 8, NA1760, II NFPA CODES: HEALTH -1 FLAMMABILITY -0 CORROSIVE -3 REACTIVITY -0======================= SECTION II -COMPONENTS =====================ETHANOL, 2-BUTOXY PEL: 25 PPM CAS #: 111-76-2 TLV: 25 PPM POTASSIUM HYDROXIDE, LIQUID PEL: NOT ESTABLISHED CAS #: 1310-58-3 TLV: NOT ESTABLISHED SODIUM GLUCONATE PEL: NOT ESTABLISHED CAS #: 527-07-1 TLV: NOT ESTABLISHED SULFONATED SODIUM SALTS PEL: NOT ESTABLISHED CAS #: 147732-60-3 TLV: NOT ESTABLISHED INERT MATERIAL PEL: NOT ESTABLISHED CAS #: 7732-18-5 TLV: NOT ESTABLISHED
And exposure to acids could accelerate the decomposing.
Any new information on this issue? Did any of the TPGs or other third parties do controlled experiments to get more clarity? This is the latest info I could find (this thread and the linked Shepherd article).
Not the case with this one.
I don’t know about MS70, but I’ve seen ammonia turn copper coins blue.
Doggedly collecting coins of the Central American Republic.
Visit the Society of US Pattern Collectors at USPatterns.com.
On another post I displayed some copper exposed to NH3 vapor which turned the sample blue, although not exactly Gem quality.
But at one time in our not too distant past, ammonia and water solution was a very common cleaning solution for residential and commercial purposes. My mother used ammonia for difficult cleaning jobs when I was growing up in the 1950's. The smell of the vapor was very noticeable in the house. I am sure that many colorfully toned coins were not solely due to sulfur bearing envelopes, but to airborne ammonia cleaning solutions as well.
OINK
Here is a raw example. It does have a nice strike through.
Forgive me for resurrecting an old thread, but I found this discussion pretty interesting. A discussion came up with a fellow forum member about a wildly blue and purple toned proof IHC that was posted on instagram. I tried to search the archives to see what the consensus was and how perception may have changed over the years, and this was the most relevant thread I could find. How has the market perception changed, if at all, since this thread was made? Are neon purple and blue IHC's widely accepted by both TPG's and CAC? Has there been any additional information that has come to light in recent years?
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I have always liked that type of toning.
I've posted this one before and although only Pf 65, in hand this is nearly cameo with a green/gold color that makes it one of a kind. It's a special coin to me !
I’m not aware of generally changed perceptions or an end to the debate on this topic.
I think it’s fair to say that some blue/purple copper coins have acquired their color naturally and others haven’t.
Mark Feld* of Heritage Auctions*Unless otherwise noted, my posts here represent my personal opinions.
@DeplorableDan
Here’s what I wrote a while back when I bought a blue Indian:
“Now, if you're as good as I know you are, you're probably all thinking two letters and two numbers: MS70. It comes together with blue Indians.
Here's my reply to that. I've read every thread I could find on the topic, and I've developed my own opinion. I'll try to detail it out here.
There are generally two stances on the topic:
1) MS70 only removes surface contamination, revealing natural blue color.
2) MS70 causes the blue color.
There are variations of these, but not many. The most common variation is similar to my stance here:
1) MS70 can cause a blue color, but not always. It must have a specific type of coin with the proper surface state to cause a blue color. The blue can also occur naturally, and this is seen frequently in untouched collections. Such an example is the Millholland Collection, where several blue Indian proofs and one 2c piece appear deep blue. The collection is quite literally the poster child for unmessed with original.
It is notable that every single Proof Indian in the Millholland Collection was partially blue, and every coin but two had at least one side majority blue.
In my opinion, I really don't care if this proof is a MS70 coin. Here's why:
1) Do I think I could tell the difference between a natural and MS70 coin? No.
2) Do I think PCGS/NGC could tell the difference? Nope.
3) What about CAC? Not them either.
4) Rick Snow and his Eagle Eye sticker that the forum almost unanimously said was better than CAC for this series and @winesteven wisely considers to be a qualifier for his exceptional Indian set? Probably not - but he also takes the stance that MS70 doesn't cause blue on Indians (he says it simply reveals it).
So if the foremost experts in this kind of grading can't tell, then we either have to throw out every blue proof original or not or just enjoy them for what they are. CAC threw out the whole bunch, and yet these proofs bring substantial premiums in the market, which clearly decides that these coins are indeed market acceptable, whether you or I like it.
I think we sometimes overestimate originality. There aren't many truly original coins out there. Consider the original thread that was here this week - not many of those were original. Given, the term "original" might have been misunderstood by a large chunk of posters
.
There's also a chance this proof is entirely original - I'd have no idea how to tell for certain. NGC didn't have an issue with it. If you simply gave me this coin and told me nothing about MS70, I'd unhesitatingly call it original. The coin has a great "skin" to it, and the toning disappears to a rich brown unless it's in the light. It has some great elevation chromatics, and looks exactly like the proofs out of the Millholland Collection and Eliasberg sets. It's exactly what I'd expect for a coin our of one of the blue proof hoards of the early 1900s.
It's also exactly what I wanted with a Proof Indian. Great color, no annoying spots, and good deep mirrors with some orange peel. These things are dang near impossible to find nice these days, and I wasn't gonna settle.”
Coin Photographer.
As a generalization, I believe Rick Snow is perfectly fine with many of the blue proof Indians. However, contrary to that, I also believe that JA at CAC is not comfortable stickering many blue proof Indians.
Steve
My collecting “Pride & Joy” is my PCGS Registry Dansco 7070 Set:
https://www.pcgs.com/setregistry/type-sets/design-type-sets/complete-dansco-7070-modified-type-set-1796-date/publishedset/213996
This is my favorite blue IHC proof which I bought from Rick Snow:
It does have his Photoseal sticker, which I feel is more credible than a green CAC bean. It is graded PR67BN.
BTW: I am in the camp who has tried to turn coins blue with MS70 and despite many attempts have had no success. I can turn them turquoise with NH3 however. Ammonia was a very common cleaning agent years ago and I suspect that it could have played a role with toning IHC proofs stored in paper envelopes.
OINK
As I stated 4 years ago in this thread, I believe 2/3 of the blue copper coins are AT and I can't tell the difference with most, so I stay away. Admittedly, part of this is that I am a RD and RB copper guy. Given that CAC hasn't beaned any of them also leads me to believe that the % is probably higher than I originally thought.
Having said that, I have a lot of respect for Rick Snow and I think OINKs coin has nice eye appeal but honestly I like the reverse color better than the obverse - that's just a personal preference.
Unfortunately, this doctoring bled into the matte proof Lincoln arena about 5 years ago, and several blue PR67BNs were "made" in a short period of time. You can look at Coinfacts and see that there is basically one blue 67BN for every year. Quite a coincidence that no PR67BNs had ever existed at PCGS for most of these dates then bam, neon blue all over the place..... JMHO
https://pcgs.com/setregistry/showcase/2819
This is interesting in that I have used MS70 experimentally on US and GB copper and bronze and have many times gotten such results very similar to the 1885 above.
Well, just Love coins, period.