Singing the Blue Hues

[TJ'S Coins]

Looking at many post 1900 silver coins, one sees hues of blue in pictures that does not readily appear under natural light or even under a single incadescent bulb unless it is tilted, twisted and turned. I do not notice the problem on older coins as I have several toned Morgans and a couple of Bust Halves with very vibrant blue from ocean, royal, navy to indigo. Have any of you noticed this?

 

Does anyone know what accounts for this phenomena?

[supertooth]

TJ'S Coins----Wanted to first compliment you on your posts. Very good info that you have provided us with----been meaning to say that.

Have noticed that the more modern coins will tone seemingly lighter colors than the older classic coins. You will see more "PASTEL" colors on coins from say the 1940's onward. Especially, the mint state or proof coinage. And these colors include a very pale blue. All of these coins are NT toned coins of which I speak. I like to now think of them as that their surfaces are more "Receptive" to that lighter colored toning. I'm not sure the chemical equations necessary to get a pastel color rather than a deeper russet [for example]. I do now know that they do occur, however. And, how you tilt the coin---in various light shadings---will determine what colors and in what depth that you see them. My own thoughts on this issue is that the planchet preparation at the mint---and the subsequent cameo appearance of the surfaces 'allows' for these lighter pastel colors to appear. In short, newer and better methods of technology in striking, have allowed the mint and proof surfaces to tone this pastel colored way. Naturally we need air, a moisture source, a sulfur sourse and gosh knows what other elements to get the various colors.

 

Also would point out that many series of coins----after the silver surface in the fields has been polished or cleaned in some way, will retone in the prettiest of colors. I think that the surfaces have again been "MADE RECEPTIVE" to acquiring that toning. But, as with a Morgan Dollar or a Barber or Bust coin, that toning will appear to be a little darker color.

 

We need to hear from Tom B on this matter. He can explain the 'toning process' like no one else here on either our boards or the PCGS boards. His posts are always excellent, true, and totally informationally correct. He can take you thru the process of light reflection and refraction off of the surfaces of the coin. He can also post the links to where all this information can be found that he has written about before. Bob [supertooth]

[James_OldeTowne]

I believe you are observing toning in progress. The thing is, a bust half has had 200 years to tone, while a Morgan has had only 100. Stick around for another 100 years, and I believe you will observe Morgans with that same level of blue toning!

 

Also, be aware that the alloying of metals in 1900 vs. 1800 was much more advanced, and I am pretty confident that simply the metal chemistry of early coins plays a large part in how they tone versus coins of later vintage.

 

The type of toning, where a coin looks normal, or even dull, at most angles, then suddenly displays lively, vibrant toning (usually blue or some related color) is referred to by many as "headlight toning". It's as if a light switch suddenly gets flipped on when certain angles of viewing are used.

 

Finally, I would like to express my apprecation to as well for being kind enough to contribute to the excellent quality of the coin boards. Thanks, TJ!

 

James

[TJ'S Coins]

You will see more "PASTEL" colors on coins from say the 1940's onward. Especially, the mint state or proof coinage. And these colors include a very pale blue. All of these coins are NT toned coins of which I speak. My own thoughts on this issue is that the planchet preparation at the mint---and the subsequent cameo appearance of the surfaces 'allows' for these lighter pastel colors to appear. In short, newer and better methods of technology in striking, have allowed the mint and proof surfaces to tone this pastel colored way. Naturally we need air, a moisture source, a sulfur sourse and gosh knows what other elements to get the various colors.

 

Thanks, Bob. Yes, that pastel blue is visible on many dimes and quarters that I have seen from the '40's through 1964. I've also noticed the pastel blue phenomena on Jefferson Nickels from the 1960's that were left in the original cellophane. There have been some outrageous coins at shows where the appear so blue that people openly question whether it is NT or AT.

 

Also would point out that many series of coins----alter the silver surface in the fields has been polished or cleaned in some way, will retone in the prettiest of colors. I think that the surfaces have again been "MADE RECEPTIVE" to acquiring that toning. But, as with a Morgan Dollar or a Barber or Bust coin, that toning will appear to be a little darker color.

 

Some of my "favorite" toned coins are ones that were actually dipped some time back and allowed to retone naturally through either placement in an album or envelope.

 

My thinking on some Peace dollars - and this only speculation - is that some with the rainbow toning may have been dipped or, in your words, "MADE RECEPTIVE" to tone in the manner that they do. I do not mean to imply that this true for every rainbow toned Peace dollar as I've seen many with a hint of rainbow album toning and the splotchy type together on the same coin which is more common for the series.

[TJ'S Coins]

I believe you are observing toning in progress. The thing is, a bust half has had 200 years to tone, while a Morgan has had only 100. Stick around for another 100 years, and I believe you will observe Morgans with that same level of blue toning!

 

Also, be aware that the alloying of metals in 1900 vs. 1800 was much more advanced, and I am pretty confident that simply the metal chemistry of early coins plays a large part in how they tone versus coins of later vintage.

 

Thanks, James! Toning is a process that naturally takes time and elements to react to a coins surface. It only makes sense that older coins will have had more time to develop that lovely, attractive patina which makes them so desirable to many of us on these boards.

 

No doubt the alloy process has made strides in the past 200 years. For instance, the purity and quality of the copper used for early coins determined if the planchets were good regarding corrosion and porosity. It only makes sense that silver alloys may also have the same improvements.

 

The type of toning, where a coin looks normal, or even dull, at most angles, then suddenly displays lively, vibrant toning (usually blue or some related color) is referred to by many as "headlight toning". It's as if a light switch suddenly gets flipped on when certain angles of viewing are used.

 

Ah, what a simple and clear definition of "headlight toning! Are you going to post it on the coin terminolgy thread?

[supertooth]

TJ----this could turn out to be a 'super' thread. I am currently waiting---not very patiently any more for 11 Morgans to come back in multi--holders from NGC. When I get them back, I hope to finish a thread that I posted not too long ago on the "TANGENT" section---entitled 'True NT story'. I mention this because it encouraged me----after finding those coins in my Whitman albums---to look for more coins that I had stored in the 1960's. I found, to my amazement, two 1964 halves. Both were in the older brown 2by2 envelopes that were common in those days. I have hundreds of coins in those envelopes still to this day. Anyway, one half was a 64 P---the other half was a 64 D. Both had been placed in those envelopes when new---and hadn't been touched since. The 64 P was beautifully toned---great eye appeal. The 64 D was also toned---differently and somewhat lesser of an eye appealing coin. My conclusion was that the 64 D planchet had to have had something different done to it than the P minted coin. The two brown envelopes were side by side---exact same conditions. Yet two completely different results. If my Morgans come back OK, I will send these two halves to be put into a two coin multi--holder. It has been a great 'teaching tool' for me---as I have been able to trace these coins from mint state just issued coins to completely toned NT coins over a period of 42 years. Absolutely knowing how they look now is a tremendous help in identifying others that look similar. But, I mention all of this because my immediate thought on those two coins when I saw them was that the mint "HAD" to have treated those two planchets differently back in 1964.

 

The Peace Dollars are known to have been acid rinsed differently than the Morgans. They say that that reason was definitely why the Peace Dollars do not tone very well. And that that blotchy brown toning that some of them get is basically what you can expect. I have many like that---in those old brown envelopes. The Peace Dollar thing is one reason why I have formulated my thoughts as to why other toning is different for different series. I think that the coins start off with a "DIFFERENT POTENTIAL" for toning. Some series is one way. Another series might bring you a different kind of toning. If my buddy Tom B does not find this thread and get into it with us---I will PM him and ask for some of his opinions to be brought here. Bob [supertooth]

[TomB]

You have been getting very insightful replies as to coinage metallurgy and preparation. Also, in response to your very good question about the difference in the quality of toning of 19th century coins vs 20th century coins, I would have to say that the ability to save coins and the major means of long-term storage play an important role in the toning process.

 

Many coins from the 19th century that you are apparently writing about, with their deeper blues and violets, are the proof issues that were not mishandled or are business strike coins that may have had a previous dip. The attractive proof pieces, with even, gradient toning of smokey blues and tans, were likely stored on or within velvet-lined trays or display cases. The chemicals contained within the velvet lining, the glues used to hold the velvet down and the acidic woods that were used to construct the holders combined over time to allow these colors to establish themselves. We must also keep in mind that not all of these proof issues are attractive, in fact, quite a few aren't good looking at all and/or have been dipped. The business strike pieces most likely spent their history in various holders since the modern coin album was not available 200 years ago. This would lead to varied storage environments and numerous toning progressions.

 

The common coin album, as we know it, started to develop in the early half of the 20th century. The various albums that developed were almost always paper-based and usually made from the cheapest grade paper available. Prior to 1970, almost all papers were sized for water repellency and ink hold out using aluminum sulfate. This was also used as a formation aid and retention chemical to hold small particulate in the paper. The amount used would typically yield a pH for the paper of around 4-4.5, which is acidic. If a dye were used to color the paper then one or more various salts were introduced such as sodium sulfate, sodium chloride or others. The function of these dyes was analogous to making the paper color-fast, such as today's clothes. Also, sulfuric acid was added to maintain a relatively stable pH of 4.0 during the papermaking process. If the pH were to drop too far, that is, become too acidic, then other compounds were used to bring it up and these included sodium aluminate, soda ash and even sodium hydroxide.

 

Exposing coins to this environment served to accelerate toning greatly and unevenly since coins could be loose-fitting or tight-fitting in the holder, could be stored in fresh or "leeched out" holders, were made more portable and thus stored in a greater variety of environments, occupied various positions within their holders that affected their ability to tone such as occupying a space next to the edge of an album page or within the middle of an album page. The mass production and usage of these albums, and other modern storage techniques, combined with the reduced value of the coins they often held, allowed many more people to save coins. Not all of these people were numismatists and not all of them treated the coins "well" in how we would think of it today. Therefore, we have a different type of toning that arises from the different storage techniques and also from the history of how each coin was handled.

 

As for present day, most paper manufacture is alkaline in nature, these are the archival safe papers that we see. In many cases these papers are neutralized by the introduction of calcium carbonate, which is added to person_having_a_hard_time_understanding_my_point or stop the ageing process. Practically speaking, paper produced over the last 20 years is fairly inert and should not tone coins in the same manner as seen previously.

 

I don't know how much of the above fits what you are seeing or how your coins were stored, but it helps to explain why there can be a different "feel" for the color that coins will tone.

[TJ'S Coins]

Bob your story on the Kennedy Halves, and I hope you post pictures of them at some point, is an excellent object lesson in toning. Your insights into the different series and even the difference in Mint bears true from anecdotal observation but also the two '64 halves you possess. I think that I can speak or all of us on the boards that we look forward to seeing some picture of your Morgans when they return.

 

Tom your posts are always so informative on both a scientific and practical level. Thanks for sharing your expertise with us on toning in the many ways that you do!

 

My 19th century blue coins are all business strikes. You give a fine overview of the possible reactions from the packaging, storage and coin cabinets of days gone by. You have also explained clearly the composition of the paper used for album storage in the 20th century and the changes over the past couple of decades. This makes a lot of sense. Also, I've never consciously thought of the fit of the coin (loose or tight) into the holder as having as much impact on the toning as it no doubt does. Likewise the leeching of the chemicals in the paper is also of a finite nature and not a constant.

 

I wonder, however, if these new albums are totally inert. I placed a shiny 1943 steel cent in the Dansco album two years ago and it is already developing a light tan tone on the obverse. Again it depends on the metal composition, humidity, temperature and storage location of the coins.

 

Some insights that I have gathered from these wonderful explanations on "Singing the Blues" is that this hue initially begins as a pastel but is slow to develop into the richer royal, ocean, cobalt, navy and indigo shades. Prior dipping of 19th century coins and subsequent storage also enhances this process. Toning is indeed a process and our knowledge of it continues to grow with observation, testing (Bob's two Kennedy's come to mind) and time. The scientific insights Tom is making into the hobby will benefit future generations of collectors.

[TJ'S Coins]

Part 2 of Singing the Blues:

 

Why do so many pick-up blue highlights in toned coined pictures that are barely if at all discernable to the naked eye?

 

I'm sure light refraction and underlying "headlight toning," as well as color adjustments on computer picture software can be reasons. I've seen many 20th century coins in pictures with lovely shades of blue that are just not there with the coin in hand. I'm not suggesting fraud on anyone's part but this Bridgeport that I posted on another thread a couple of days ago is more blue in this poor scan (and even more vibrant in the professional picture that drew me to the coin) than it is under light

 

 

 

Can anyone explain?

[supertooth]

TJ's coins----I really have gotten into this thread----truly excellent!! I guess that one day I will finish the necessay equations---I get motivated---buy another old coin cleaning book----pull out my old Merc book. Then I write a whole bunch of equations down. Try to remember whether they are correct or not. Then send another PM to my friend, Tom B. When it is over, I am still not totally satisfied. You see, I treat life like a Math problem. But toning is not a Math problem that is easily solved. And then you must remember that the science of light refraction etc. etc. was stuff that I studied between about 1965 and 1972. Oh yes, I had it all---and once upon a time could have repeated it without skipping a beat. But---no longer. Yet one day I may still come up with something that sort of makes complete sense. In the meantime I will quote a line that my friend sent to me in one of my more dramatic NT periods. I give Tom B full credit for it and I think it is a line which best explains why the Math of the toning process is sooooo elusive. He wrote it to me while I was explaining about those toned Morgans which are, till this very day, still sitting at NGC in Florida. Here is the quote: " That is one of the truly wonderful, yet continuously vexing things about toning, you can never fully anticipate the look you will find and can never completely explain how it happened." To me this pretty much sums it up in a nutshell. One day I would like to put some Math with it. But, that aside, it does sort of explain why things can be one way with one series of coins---while it can be completely different with a different series. Why some tone like Peace Dollars do most of the time and why Morgans do what they do. I might add that I think that my words of yesterday are also pretty telling. That the surfaces of certain series are more--or less--RECEPTIVE---to certain kinds of toning. And therefore to certain colors within the color spectrum. But, like Tom B and I have talked about---when you add in all the other external possibilities into the equation----every situation and EVERY COIN becomes its own individual circumstance. Anyway, this is where I am with the problem. I hope to be further along one day down the road. Bob [supertooth]

[TJ'S Coins]

Bob, I think you explained beautifully why I love collecting toned coins when you wrote:

 

"when you add in all the other external possibilities into the equation - every situation and EVERY COIN becomes its own individual circumstance"

 

One could argue that every coin is unique in one way or another taking into account, strike, luster, errors, wear, etc. But toning makes that quickly evident in a wonderful way that, for me, makes collecting toned coins very exciting.

 

The science behind the toning is also intriguing too. I aced high school chemistry and physics but pursued a non-scientific career and only took one physics class in college. I only wish I could remember all that I was taught. That's why I'm glad to have you and Tom providing such excellent material for us amateurs in that field.

 

BTW, glad you find this thread exciting