MS70 and blue copper test (V1)

stealer · July 24, 2017 4:33PM

TL;DR, tried MS70 on a bunch of copper Lincolns, nothing conclusive was shown, need to do further tests. Was able to get one of the coins to turn blue.

Setup:
I grabbed 9 copper Lincolns I had lying around and performed the following actions:

apply MS70 to the obverse
let sit for ~2 minutes
roll Qtip over the surfaces
soak coins in warm tap water and pat dry

Photos:
Before:

After MS70 but before soak:

After Warm water soak + pat dry:

Results:
The really dark coin in the bottom right of the first two images was the only one to exhibit any interesting effects after the application of MS70 - the rest remained roughly unchanged. What's interesting is that I didn't notice any change of color until after the warm soak and pat dry. My current hypothesis is that the tarnish on the darker copper pieces leave some film that reflects blue light that can't be removed by MS70. Pardon me if I butchered the technical language, it's been a while since I took optics.

Overall, based on a sample size of one (), it seems like MS70 helps to bring out the filmy looking toning on copper that's so hot right now.

Notes for future tests:

I will take better images next time, I promise
I want to test multiple darkly toned coins

1630Boston · July 24, 2017 4:45PM

Interesting experiment

You · July 24, 2017 5:11PM

Blue is not a possible natural color for business strike copper to tone. It is caused by the MS70, not revealed by it. The blue color can be removed.

bolivarshagnasty · July 24, 2017 6:02PM

Here we go again. Cue the Eagle Eye guy.

spacehayduke · July 24, 2017 6:28PM

@You said:
Blue is not a possible natural color for business strike copper to tone. It is caused by the MS70, not revealed by it. The blue color can be removed.

Natural toning/color is due to thin film refractive index, independent of metal. Copper can tone blue naturally and does, countless examples of such. Here is a thread on the theory behind thin film colors on metal:

https://forums.collectors.com/discussion/708296/towards-an-understanding-of-the-color-progression-on-toned-coins

MS70 can also cause a blue coloring of the surface that goes away with time - different process different results.

Best, SH

You · July 24, 2017 7:00PM

@spacehayduke said:

@You said:
Blue is not a possible natural color for business strike copper to tone. It is caused by the MS70, not revealed by it. The blue color can be removed.

Natural toning/color is due to thin film refractive index, independent of metal. Copper can tone blue naturally and does, countless examples of such. Here is a thread on the theory behind thin film colors on metal:

https://forums.collectors.com/discussion/708296/towards-an-understanding-of-the-color-progression-on-toned-coins

MS70 can also cause a blue coloring of the surface that goes away with time - different process different results.

Best, SH

The main discussion point of that post is directed towards silver coins. To quote adamlaneus from that thread, "Don't forget that a coin that contains copper will also tone in a way specific to copper. Copper tends to look...well...coppery. It's corrosion products are comprised of colorful minerals. A 90% silver coin will tone a little differently than a 100% silver coin, providing that the copper was involved with the toning. Copper coins, Gold coins...they tone rather differently than Silver coins." You will never see a gold coin with cyan toning.

To quote Sunnywood himself, the author of the post, "Copper will be noticeably different due to its own color. Our perception of color does not reflect something inherent in a substance, but rather its ability to absorb light at various frequencies. Even paint pigments appear the way they do for this reason. In other words, yellow paint is not inherently yellow; rather it is its ability to absorb blue light that makes it appear yellow when illuminated by full-spectrum white light. Copper appears red-orange because of its ability to absorb some blue and green light. Therefore, the reflected light from a copper surface will not have all the same wavelengths present as light reflected of a bright silver surface. This in turn affects the interference progression. There will still be a thin film phenomenon, and a color progression, but somewhat modified from the one for silver coins.
On nickel I would expect the progression to be closer to that of silver, but I have not studied enough toned nickel to verify this.
My observation & toning classification system were intended only for use on silver coins, at least for now."

I stand by my original statement. Business strike copper will not naturally appear blue unless it has been treated with MS70 or something similar at some point in the past. Proof copper is a whole different story, although I'm not entirely sure why.

spacehayduke · July 25, 2017 4:47AM

You, you are overinterpreting the text of that post by SW within a thread with alot more detail and missing the point of thin film refraction. Believe what you want, but copper can have a wide range of toning colors, just as silver and gold in the right conditions, and that, turns out, also includes the color blue. It depends on what light wavelengths are reflected off the thin film metal surface, nothing more. Blue is part of the visible light spectrum just as are yellow, green, red, purple. Copper, like silver, can have all of those colors - how it is distributed on the surface is dictated by how the coin toned and the thickness of the toned film. So what you are saying is that there is full absorption at blue wavelengths yet the rest of the wavelengths in the visible spectrum refract on toned surfaces of copper? Proof copper is still copper, the same copper used in buisness strikes (element Cu), so you can't use one type of copper coin and agree it can have blue toning from thin films and then eliminate another type of copper coin. Clearly, the blue from natural toning/thin film has a very different characteristic than the blue color that can be imparted by MS70 under the right conditions. But as I note, above, that appears to be a chemical reaction and does not necessarily stay on the surface of the coin over time.

Now is the natural toning observed on copper different from that of silver, nickel, etc.? Absolutely, but is not what this thread was supposed to be about.

Best, SH

brg5658 · July 25, 2017 9:02AM

@You said:
Blue is not a possible natural color for business strike copper to tone. It is caused by the MS70, not revealed by it. The blue color can be removed.

Absolute nonsense.

Insider2 · July 25, 2017 9:38AM

@spacehayduke said: "Natural toning/color is due to thin film refractive index, independent of metal. Copper can tone blue naturally and does, countless examples of such. MS70 can also cause a blue coloring of the surface that goes away with time - different process different results.

This seems reasonable; yet IMO over-stated as I believe the vast majority of "blue" copper has been "made" in the last three decades and has finally become "market acceptable" in the last decade and a half.

@brg5658 said: "Blue is not a possible natural color for business strike copper to tone."

I disagree, velvet or cotton, plus time and environment can turn copper blue.

@brg5658 said: "It is caused by the MS70, not revealed by it. The blue color can be removed."

I agree with this. I have also done the OP's experiment with very limited results. One or two out of 20 old circulated Lincoln cents from the '40's and 50's. However, this blue color is very commonly produce when cleaning vintage AU to Unc copper coins from all countries when there is NO INTENTION to produce the color! Additionally, I suspect warmth is involved, such as hot MS-70.

@brg5658 said: Absolute nonsense.

I think I know who this poster is and I'll say he is very qualified to post opinions! That said, he should know that some words (never, always, absolute) should probably NEVER (LOL) be used in numismatics.

SamByrd · July 25, 2017 9:49AM

I have found for certain MS70 can affect red copper. Circulated copper it really seems neutral. Eons ago the coin in the image I did a 20 second dip in MS70. Distilled water rinse and then acetone rinse. This one was an ugly AU coin. I only have the after image unfortunately and this coin has been stable more than a decade. It did become bluish and still ugly though ANACS put it in a small white holder as a MS63.

brg5658 · July 25, 2017 9:59AM

@Insider2 said:
@spacehayduke said: "Natural toning/color is due to thin film refractive index, independent of metal. Copper can tone blue naturally and does, countless examples of such. MS70 can also cause a blue coloring of the surface that goes away with time - different process different results.

This seems reasonable; yet IMO over-stated as I believe the vast majority of "blue" copper has been "made" in the last three decades and has finally become "market acceptable" in the last decade and a half.

@brg5658 said: "Blue is not a possible natural color for business strike copper to tone."

I disagree, velvet or cotton, plus time and environment can turn copper blue.

@brg5658 said: "It is caused by the MS70, not revealed by it. The blue color can be removed."

I agree with this. I have also done the OP's experiment with very limited results. One or two out of 20 old circulated Lincoln cents from the '40's and 50's. However, this blue color is very commonly produce when cleaning vintage AU to Unc copper coins from all countries when there is NO INTENTION to produce the color! Additionally, I suspect warmth is involved, such as hot MS-70.

@brg5658 said: Absolute nonsense.

I think I know who this poster is and I'll say he is very qualified to post opinions! That said, he should know that some words (never, always, absolute) should probably NEVER (LOL) be used in numismatics.

@Insider2 , I did NOT say the things you attribute to me. I was replying to the post by @You . I did say that the post by @You was complete nonsense.

If you're going to quote someone, get it right.

Insider2 · July 25, 2017 10:43AM

@brg5658

Nevermind...very sorry. Thanks, for correcting my heinous error. I could not believe what I thought you posted. For what it's worth, my esteem for you is restored. Very sorry to take up your better-used time needed to reply further due to my error.

@SamByrd I think your coin is nice the way it is.

Insider2 · July 25, 2017 10:51AM

@brg5658 said:

@You said:
Blue is not a possible natural color for business strike copper to tone. It is caused by the MS70, not revealed by it. The blue color can be removed.

Absolute nonsense.

Sorry I have the need to partially redeem myself as now I shall ask you to explain what exactly you think is nonsense in the post above other than " Blue is not a possible natural color for business strike copper to tone."

Do you believe a blue color on copper can be caused by MS-70? If yes, can it be easily removed?

In which case, only the first sentence posted by @You is "absolute nonsense. " Agree?

OldIndianNutKase · July 25, 2017 11:11AM

My test results with MS70 and bronze (95% Cu/5% Tn Zn) are in total agreement with the OP. My testing was on UNC 1960's vintage Lincoln cents which I own in abundance. My est was MS70 / wash / acetone dip. No positive result on RD coins out of 20-30 coins. Dark brown copper was not changed much either. Lightly toned BR coins did get some color, but it was not always blue.

Bluish toning in IHC PR BN and RB coins is much more common than on MS coins. There have been many explanations for this including sulfer in mint tissue paper as packaged by the mint, storage envelopes used by collectors (but MS coins were stored this way as well), and atmospheric contaminants like dilute ammonia fumes from commonly used household cleaning agents early in the twentieth century. Bronze coins definitely turn blue in the presence of NH3 fumes in my testing.......but not a particularily nice blue.

And check out this 1856 1C PR65BN:

Very pretty blue reverse and just light blue on the obverse. I really doubt the blue on this coin was created by MS70.

OINK

Rexford · July 25, 2017 11:19AM

Never mind

brg5658 · July 25, 2017 11:29AM

@Insider2 said:

@brg5658 said:

@You said:
Blue is not a possible natural color for business strike copper to tone. It is caused by the MS70, not revealed by it. The blue color can be removed.

Absolute nonsense.

Sorry I have the need to partially redeem myself as now I shall ask you to explain what exactly you think is nonsense in the post above other than " Blue is not a possible natural color for business strike copper to tone."

Do you believe a blue color on copper can be caused by MS-70? If yes, can it be easily removed?

In which case, only the first sentence posted by @You is "absolute nonsense. " Agree?

I believe that some blue copper may be due to MS70. @You said it [i.e., apparently "all" blue copper] was caused by MS70. He left no other option for naturally toned blue copper. Thus, I disagreed with both parts of his post, and stated they were nonsense accordingly.

People who dogmatically declare all blue copper to be the work of MS70 are ignorant and clearly don't collect copper.

You · July 25, 2017 11:39AM

@OldIndianNutKase said:
And check out this 1856 1C PR65BN:

Very pretty blue reverse and just light blue on the obverse. I really doubt the blue on this coin was created by MS70.

I said business strike. That is natural color.

@brg5658 said:
People who dogmatically declare all blue copper to be the work of MS70 are ignorant and clearly don't collect copper.

Not all blue copper, just business strike blue copper.

@Insider2 said:
For what it's worth, my esteem for You is restored.

Thanks friend

brg5658 · July 25, 2017 11:43AM

@You said:

@brg5658 said:
People who dogmatically declare all blue copper to be the work of MS70 are ignorant and clearly don't collect copper.

Not all blue copper, just business strike blue copper.

@You , you may want to revisit a remedial physics textbook, as you seem to not understand science.

I think the point some here seem to be missing is that an experiment showing that MS70 sometimes causes copper to turn blue, does not equate with all blue copper having been caused by MS70.

A implies "B", does not mean that all "B" are caused by A.

You · July 25, 2017 11:53AM

@brg5658 said:
I think the point some here seem to be missing is that an experiment showing that MS70 sometimes causes copper to turn blue, does not equate with all blue copper having been caused by MS70.

A implies "B", does not mean that all "B" are caused by A.

Yes, I understand basic logic. I am not making my argument with this post as a foundation. Again, I do not know why proof copper coins can tone blue, but my hypothesis is that they simply reflect light differently because the dies are polised. I have noticed that the more mirror-like a proof copper coin is, the greater capacity it has to exhibit blue color.

Insider2 · July 25, 2017 11:57AM

@brg5658, I shall end this but you did bot answer the questions in my post defending a part of @You's post; however, I can read between the lines and it appears you agree with these:

Color on copper CAN be caused by MS-70 and it can be easily removed?

In which case, only the first sentence posted by @You is "absolute nonsense. "

Insider2 · July 25, 2017 12:01PM

@You said: "Thanks friend."

You are welcome but I was referring to @brg5658.

OldIndianNutKase · July 25, 2017 12:04PM

@You said:

@OldIndianNutKase said:
And check out this 1856 1C PR65BN:

Very pretty blue reverse and just light blue on the obverse. I really doubt the blue on this coin was created by MS70.

I said business strike. That is natural color.

Soooo, here is a blue toned business strike........

As I understand the OP premise, will MS70 turn a copper coin blue? Above is a business strike cent that has nice blue color. Very difficult admittedly with large cents and the coin above could be this color because of MS70. Lot's of MS large cents for somebody to experiment with? My point is that if MS70 does not add color to an RD coin then it cannot add color to BN coin. MS70 will remove toning "layers" that cover the blue layer. I do not think that MS70 will remove the blue and I am pretty sure that acetone will not as well.

OINK

Insider2 · July 25, 2017 12:13PM

@OldIndianNutKase said:

@You said:

@OldIndianNutKase said:
And check out this 1856 1C PR65BN:

Very pretty blue reverse and just light blue on the obverse. I really doubt the blue on this coin was created by MS70.

I said business strike. That is natural color.

Soooo, here is a blue toned business strike........

As I understand the OP premise, will MS70 turn a copper coin blue? Above is a business strike cent that has nice blue color. Very difficult admittedly with large cents and the coin above could be this color because of MS70. Lot's of MS large cents for somebody to experiment with? My point is that if MS70 does not add color to an RD coin then it cannot add color to BN coin. MS70 will remove toning "layers" that cover the blue layer. I do not think that MS70 will remove the blue and I am pretty sure that acetone will not as well.

OINK

Please DO NOT try this; BUT... Take a Q-tip and put a drop of Coin Care on the field in front of the nose. Take an image of the brown circle that occurs where the Care was on the surface. Then swish your coin in some acetone and take another image. It should return to the original state.

The reason you should not do this is because I already know what the coin will look like in the "test" and it is best to let a specialist (not me) do this so he/she can make sure it goes back to a perfectly natural "blue look" with no evidence of chemical flow.

You · July 25, 2017 12:13PM

@OldIndianNutKase said:

@You said:

@OldIndianNutKase said:
And check out this 1856 1C PR65BN:

Very pretty blue reverse and just light blue on the obverse. I really doubt the blue on this coin was created by MS70.

I said business strike. That is natural color.

Soooo, here is a blue toned business strike........

As I understand the OP premise, will MS70 turn a copper coin blue? Above is a business strike cent that has nice blue color. Very difficult admittedly with large cents and the coin above could be this color because of MS70. Lot's of MS large cents for somebody to experiment with? My point is that if MS70 does not add color to an RD coin then it cannot add color to BN coin. MS70 will remove toning "layers" that cover the blue layer. I do not think that MS70 will remove the blue and I am pretty sure that acetone will not as well.

OINK

That is in no way a circulation/business strike, but that color is natural and not caused by MS70. I know what blue from MS70 usage looks like. If someone can show me an actual business strike with blue color that doesn't look like what I know blue from MS70 to look like, I will amend my statements, but I'm yet to see one.

Insider2 · July 25, 2017 12:19PM

Well, progress! MS-70 does not turn 'Red" copper blue. However, I cannot say for sure. I have used MS-70 on red Unc's . I don't have a clue what would happen if the coin were put away for a few (?) years.

OldIndianNutKase · July 25, 2017 12:25PM

@You said:
That is in no way a circulation/business strike, but that color is natural and not caused by MS70. I know what blue from MS70 usage looks like. If someone can show me an actual business strike with blue color that doesn't look like what I know blue from MS70 to look like, I will amend my statements, but I'm yet to see one.

Look up cert. no. 29676927. You and a few others are taking the position that MS70 will turn a copper coin blue. It would be much more helpful if you post some images of coins that you turned blue with MS70. And before pictures would also be helpful.

OINK

You · July 25, 2017 12:29PM

@OldIndianNutKase said:

@You said:
That is in no way a circulation/business strike, but that color is natural and not caused by MS70. I know what blue from MS70 usage looks like. If someone can show me an actual business strike with blue color that doesn't look like what I know blue from MS70 to look like, I will amend my statements, but I'm yet to see one.

Look up cert. no. 29676927. You and a few others are taking the position that MS70 will turn a copper coin blue. It would be much more helpful if you post some images of coins that you turned blue with MS70. And before pictures would also be helpful.

OINK

I looked it up, and just as I said, it's PR64BN - Proof, not business strike. I don't have any pictures because I remove the blue color afterwards.

keyman64 · July 25, 2017 12:29PM

I experimented with MS70 and some RED copper coins about a year ago, so I could maybe learn a few things. My efforts were with 1960s PROOF Cents.

I tried a few things. that included: Dipping, Air Drying, Blow Dryer, Warm Water Rinses, different combinations and sequences with several different tries. The results: Nothing happened.

I never tried experimenting with RB or BN Proof Cents.

Here are two PCGS Blessed Blue Toned Proof Cents that I own. They look mostly brown until you tilt them into a light and that is when you see the colors.

PR67BN

PR66BN

keyman64 · July 25, 2017 12:33PM

Here is an example of a coin that many people here questioned as being as MS70 or at least something fishy. I sent it into PCGS in 2015 and it did come back as Questionable Color. Part of my education....

You · July 25, 2017 12:35PM

So all I'm seeing are proof coins in this thread. Hmmm.....

You · July 25, 2017 12:36PM

@keyman64 said:
Here is an example of a coin that many people here questioned as being as MS70 or at least something fishy. I sent it into PCGS in 2015 and it did come back as Questionable Color. Part of my education....

Yep, that's artificial for sure. Not sure if MS70 though.

asheland · July 25, 2017 12:41PM

Insider2 · July 25, 2017 12:48PM

@You said:

@keyman64 said:
Here is an example of a coin that many people here questioned as being as MS70 or at least something fishy. I sent it into PCGS in 2015 and it did come back as Questionable Color. Part of my education....

Yep, that's artificial for sure. Not sure if MS70 though.

That verifies something about NT and AT that I will not share here.

Insider2 · July 25, 2017 12:54PM

@OldIndianNutKase said: "... a few others are taking the position that MS70 will turn a copper coin blue. It would be much more helpful if you post some images of coins that you turned blue with MS70. And before pictures would also be helpful."

I have had this result on copper: Lustrous brown to lustrous blue but it was not done on purpose - it just happened. A friend who has had the same results many times before is going to take your challenge and publish his results in Numismatic News.

You · July 25, 2017 1:06PM

@Insider2 said:
That verifies something about NT and AT that I will not share here.

I'm guessing you were wondering whether color from MS70 counts as artificial? It's induced artificially via a chemical, so yes. PCGS lets them get by sometimes (which is disappointing) but they'll often end up in Questionable Color holders.

OldIndianNutKase · July 25, 2017 1:15PM

@You said:

I looked it up, and just as I said, it's PR64BN - Proof, not business strike. I don't have any pictures because I remove the blue color afterwards.

You are correct. The coin was listed incorrectly in CoinFacts as a business strike.

I mostly collect proof coins and not business strikes. But here is one that I bought lately and am open to everyone's opinion as to it's blue obverse......but no blue on the reverse:

Coin is raw.

OINK

You · July 25, 2017 1:36PM

@OldIndianNutKase said:

@You said:

I looked it up, and just as I said, it's PR64BN - Proof, not business strike. I don't have any pictures because I remove the blue color afterwards.

You are correct. The coin was listed incorrectly in CoinFacts as a business strike.

I mostly collect proof coins and not business strikes. But here is one that I bought lately and am open to everyone's opinion as to it's blue obverse......but no blue on the reverse:

Coin is raw.

OINK

Looks like MS70. I can PM you how to remove the blue if you would like to test it - it won't harm the coin or the toning if it is natural. Then you can post a pic of it afterwards.

Insider2 · July 25, 2017 2:06PM

@You said: "I can PM you how to remove the blue if you would like to test it."

Why use a PM as several ways to remove it have been posted on the Internet. Perhaps you would like to share your method.

BTW In my limited experience, "two tone coins" are not well received. Additionally, the "pink" color in the image is not good either but that is probable just the lighting.

stealer · July 25, 2017 3:21PM

Feel free to post your favorite methods for removing blue, and I will give them a go on some blue LC's

Insider2 · July 25, 2017 4:24PM

LOL.

Hold your thumb and forefinger about an inch and a half apart. That should fit all sizes in step 2
Place your thumb on the base of one side of your nose and your forefinger on the other.
Squeeze them together.
Now rub your coin with your greasy fingers.

Note: Do not try this a home as you may have hairlined your NOW BROWN coin.

Actually, take a Q-tip and rub the side of your nose. Just touch the greasy Q-tip to a very tiny part of the blue surface on the coin's reverse rim. This way, you will see what happens and your coin will still be blue. After the test, put some acetone on the spot to remove the grease and restore the blue color.

I've heard there are other ways to remove the blue (why would you want to). Perhaps some members can educate us.

spacehayduke · July 25, 2017 4:50PM

Here are some copper tokens with blue tones and other colors, not proofs, I don't collect US issue copper so don't have any examples so copper tokens will have to do.

If one were to go to some of the well known dealer sites for small cents, one would see many buisness strike copper with blue tones and other colors as well. Are they as common as those with out blue, red, purple tones? No. But they do exist and most of which are likely to not be MS70ed.

You · July 25, 2017 7:00PM

@spacehayduke said:
Here are some copper tokens with blue tones and other colors, not proofs, I don't collect US issue copper so don't have any examples so copper tokens will have to do.

If one were to go to some of the well known dealer sites for small cents, one would see many buisness strike copper with blue tones and other colors as well. Are they as common as those with out blue, red, purple tones? No. But they do exist and most of which are likely to not be MS70ed.

Unfortunately those do look MS70ed to me. I think you underestimate how widespread MS70 usage is. The HT-294 is like a perfect example of what MS70 generally looks like.

@Insider2 said:
LOL.

Hold your thumb and forefinger about an inch and a half apart. That should fit all sizes in step 2

Place your thumb on the base of one side of your nose and your forefinger on the other.

Squeeze them together.

Now rub your coin with your greasy fingers.

Note: Do not try this a home as you may have hairlined your NOW BROWN coin.

Actually, take a Q-tip and rub the side of your nose. Just touch the greasy Q-tip to a very tiny part of the blue surface on the coin's reverse rim. This way, you will see what happens and your coin will still be blue. After the test, put some acetone on the spot to remove the grease and restore the blue color.

I've heard there are other ways to remove the blue (why would you want to). Perhaps some members can educate us.

This is not a recommended method, do not do it. And you remove the blue because it is artificial....

EagleEye · July 25, 2017 8:15PM

@bolivarshagnasty said:
Here we go again. Cue the Eagle Eye guy.

Naw, I'm not going to comment. I've said all there is to say. Anyone else who says different, including my friend and table partner at the ANA, is just plain wrong. He said to his class at Summer Seminar that exposing the copper to air brings out the blue tone! I had to correct him, which I shouldn't have to do.

ChrisRx · July 25, 2017 8:23PM

Let's sum up blue copper:

Some are AT some are NT.

To say all blue toned copper is AT (or ms70'd) is just nonsense.

brg5658 · July 25, 2017 8:24PM

Sadly, this thread has been turned into a gigantic facepalm due to the personal ill-informed opinions of @You .

Those of us who actually collect copper know better. Oh well. I'll be spending my time in other more useful places. Cheers.

Insider2 · July 25, 2017 8:39PM

Thanks for posting Rick. You've had this battle. Those of us who have turned copper coins blue unintentionally with MS-70 have seen the proof it can happen with our own eyes. The fact is, some copper is probably blue naturally, as I've seen iridescent "blue" copper still in old collections that no one touched for several years. I've also turned coins blue myself (by mistake) and quickly made them natural brown again.

As I posted above, a professional numismatist friend is going to put "before" and "after" and "back to before" images in an article. He said he needs to find a few world coins to play with.

Finally, when he turns a dull, brown copper coin iridescent blue and turns it back to lustrous brown THAT WILL PROVE NOTHING except it can be done! The final arbitrator will be the coin market and the TPGS. It is they, and you for one, who try to determine AT or NT. Look around, even in this thread, as today we can see the results of these OPINIONS.

Edited for clarity 7/26

Insider2 · July 25, 2017 8:42PM

@brg5658 said:
Sadly, this thread has been turned into a gigantic facepalm due to the personal ill-informed opinions of @You .

Those of us who actually collect copper know better. Oh well. I'll be spending my time in other more useful places. Cheers.

BYE. :

jtlee321 · July 25, 2017 10:19PM

With all the experts in here, can someone tell me if this coin is natural or caused by MS70? It's a business strike 1899 Indian Cent that when viewed under normal lighting conditions appears brown in color. When the coin is tilted and the light is reflected directly to the eye, an iridescent blue with magenta pops. My understanding is that the so called blue coins caused by MS70 retain the blue color no matter the angle you hold the coin to the light.

I have yet to send this coin to PCGS and I may not, but it's one that I bought on eBay back when I first started getting back into this hobby.

Normal lighting

Reflected lighting

You · July 25, 2017 11:51PM

@jtlee321 said:
With all the experts in here, can someone tell me if this coin is natural or caused by MS70? It's a business strike 1899 Indian Cent that when viewed under normal lighting conditions appears brown in color. When the coin is tilted and the light is reflected directly to the eye, an iridescent blue with magenta pops. My understanding is that the so called blue coins caused by MS70 retain the blue color no matter the angle you hold the coin to the light.

I have yet to send this coin to PCGS and I may not, but it's one that I bought on eBay back when I first started getting back into this hobby.

Normal lighting

Reflected lighting

MS70. Check your PMs.

spacehayduke · July 26, 2017 5:09AM

@You said:

@spacehayduke said:
Here are some copper tokens with blue tones and other colors, not proofs, I don't collect US issue copper so don't have any examples so copper tokens will have to do.

If one were to go to some of the well known dealer sites for small cents, one would see many buisness strike copper with blue tones and other colors as well. Are they as common as those with out blue, red, purple tones? No. But they do exist and most of which are likely to not be MS70ed.

Unfortunately those do look MS70ed to me. I think you underestimate how widespread MS70 usage is. The HT-294 is like a perfect example of what MS70 generally looks like.

Keep living the dream..................

spacehayduke · July 26, 2017 5:11AM

@You said:

@jtlee321 said:
With all the experts in here, can someone tell me if this coin is natural or caused by MS70? It's a business strike 1899 Indian Cent that when viewed under normal lighting conditions appears brown in color. When the coin is tilted and the light is reflected directly to the eye, an iridescent blue with magenta pops. My understanding is that the so called blue coins caused by MS70 retain the blue color no matter the angle you hold the coin to the light.

I have yet to send this coin to PCGS and I may not, but it's one that I bought on eBay back when I first started getting back into this hobby.

MS70. Check your PMs.

You honestly have no idea, show us some proof from your own experiments YOU. Myths are hard to die in numismatics.

MS70 and blue copper test (V1)

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