@Insider2 said:
Rick is on Vacation but it is time to "bump this thread."
So far I think we can all agree that "woodies" are caused by an improper mixing of a coin's alloys. I posted an image of block crystals of a different composition from the surrounding surface. Crystals in metal are common and depend on cooing/age/whatever.
I have a problem calling these crystals "ORANGE PEEL" as used by metallurgists because numismatists use that term for another characteristic found on our coins.
That caused this thread to evolve into a discussion of "orang peel" and its causes. One member has stated it is not found on silver coins. This is NOT TRUE! Some say the effect is caused by the annealing temperature of the planchet. Others believe it is due to the dies. BOTH MAY BE CORRECT.
However, in another thread here, Mr. Carr made some comments on a Peace dollar (with orange peel) he made and said it resulted from his die. I'm going to try to find out how to paste my question to him and his answer into this thread. I know I'm suppose to create a file first but....
Look on the thread : Dan Carr's Latest, pp#66 July 22 for his comments about "Orang Peel."
Nope. I'm requesting modern surface analysis, not something that is 50-year old hearsay.
It is similar unquestioning acceptance of "ancient revealed wisdom" that has been detrimental to numismatics for years. If he were alive Wally Breen would award you a "certificate of authenticity" - for a fee, of course. Simply because you or I make a claim of knowing the cause of "wood grain" does not make it a fact. There is no challenge - only a desire for all to know objective truth. Your assumption might be correct, but the "witnesses" wrote nothing and they are all dead.
Objectively, there is no right or wrong answer to the question; results of modern examination will reveal the answer.
The truth can be determined by modern nondestructive metallurgical analysis and professional data analysis.
I disagree. The cause of the woodgrain effect is extremely important. Unfortunately,I forgot to check your book last night to see if it is addressed.
In the meantime, what you are requesting [**"I'm requesting modern surface analysis, not something that is 50-year old hearsay."] has already been done long ago by the Mint Laboratory. Those old dead guys are probably rolling over in their graves at this remark. Nevertheless, I'm also one who weighs the source and content of anything I read.
As I wrote, I'm sure you will stumble across records of their analysis some day in your research. Until then. you can believe that the "gold" color streaks and inclusions are actually impurities made of gold.
Nope. You continue to reject making decisions on facts, not hearsay and speculation. What is it you fear? Where does the emotional tension originate that obstructs open-minded investigation using the latest technology? You, 'insider2' must make that examination.
Your beef is with the Treasury Dept. conclusions. I cannot help you or I would tell you where to look. Fortunately, you are a much better researcher than I'll ever be. I do agree that this information SHOULD ALREADY BE in a book about the Mint and coin making or in a book on errors. Unfortunately, it never occurred to us to write about "woodies" in our old ANACS column. In hindsight, It would have been a great topic but at the time, there was no mystery as to their cause or composition. Sort of like writing about a coin struck on a clipped planchet. It seemed that virtually everybody knew about them and their cause when teaching Summer Seminar. While clips are mentioned in all the references about how coins are made - If I remember - "woodies" may not have been. If they were, the conclusion was they resulted from an improper alloy mixture. Based on what we learned at the Mint, that's also what we taught in class. I'll try to dig out some of my old books on the minting process and error coins to see if I can find something to quote.
AND...This is something I'll agree on: Just because "everybody knows" or something has "always" been considered to be 100% true and is previously published, settled info, does not exclude it from being questioned and tested. So go for it and best of luck. Perhaps a "Go-Fund-Me" page. I'll donate.
There's nothing to add, insider2. Rejecting empirical testing and data analysis is illogical and counterproductive.
People in "the business" ought to be queuing at the chance to make a discovery and be a leader in numismatic knowledge. But, all I've heard are trilling tree frogs in the humid summer night.
@RogerB said:
There's nothing to add, insider2. Rejecting empirical testing and data analysis is illogical and counterproductive.
People in "the business" ought to be queuing at the chance to make a discovery and be a leader in numismatic knowledge. But, all I've heard are trilling tree frogs in the humid summer night.
You paint a very poetic image.
While I agree completely with your post, no one needs to prove the earth is not the center of the universe anymore. Carry on...
I'm actually very surprised that some numismatist has not published results on the woodie and shellcase phenomena from a metallurgical analysis perspective. I would think it would be pretty easy to do if you have access to an XRF or similar machine. The result I saw on shellcase were fairly definitive, since those elements found are not supposed to be in the mix. Perhaps the woodies won't be so easy to analyze? If what we are talking about metallurgically is indeed a mixing variance compounded by rolling, then the difference between colors could be relatively small differences in composition of the same elements. We're talking mostly Cu, with a small amount of Sn and Zn, where the ratio of Sn and Zn are not completely controlled, only the sum of the two. Sn and Zn tone differently from each other, and both differently from Cu, but all 3 may be present in a sample. The analysis would need to be shallow to the surface, and would look for relative proportions of Cu/Sn/Zn. It seems within the capability of a decent XRF.
PM me for coin photography equipment, or visit my website:
@rmpsrpms said:
I'm actually very surprised that some numismatist has not published results on the woodie and shellcase phenomena from a metallurgical analysis perspective. I would think it would be pretty easy to do if you have access to an XRF or similar machine. The result I saw on shellcase were fairly definitive, since those elements found are not supposed to be in the mix. Perhaps the woodies won't be so easy to analyze? If what we are talking about metallurgically is indeed a mixing variance compounded by rolling, then the difference between colors could be relatively small differences in composition of the same elements. We're talking mostly Cu, with a small amount of Sn and Zn, where the ratio of Sn and Zn are not completely controlled, only the sum of the two. Sn and Zn tone differently from each other, and both differently from Cu, but all 3 may be present in a sample. The analysis would need to be shallow to the surface, and would look for relative proportions of Cu/Sn/Zn. It seems within the capability of a decent XRF.
These coins are so cheap that I would take one with a large streak and start milling off the parts of the coin (the streak can run deeply into the surface) until I was left with a tiny sliver of "off-color" metal. Then, I'd melt it and do the analysis. I have an Indian cent with several large blocks of yellow metal - one is laminating from the surface.
Any thing could happen at the mint factory when they were doing all the preparations, Impurities could get rolled into the strip. Over the years, I've seen gold coins with silver streaks that were struck into the coin and not part of the alloy. I've seen Indian's and Lincoln's with the same thing. Struck thru errors don't look anything like a "woodie" when examined under magnification.
I am aware of tests conducted on gold coins, none on copper coins.
One thing that I am fairly certain of is that there is more than one "right" answer as to the cause of woodgrain toning. After studying how copper coins tone, and listening to the more science minded posters here over the years, I've learned that copper (bronze) is too unpredictable to be able to explain with precision the various looks and toning of copper coins. So nothing short of modern tests can provide an objective answer to woodgrain. I've also learned to distrust "common knowledge" in the numismatic world, or "numislore" as I call it. It pervades our hobby, and needs to be exorcized.
There are too many variables in the minting process to assume that improper alloy mix is the root cause in all cases. Woodgrain could possibly be caused by contaminants in the alloy, lubricant contamination in striking, contamination in the rolling or drawbench process, improper washing or pickling of planchets, improper rinsing or drying of planchets, etc.
Here is what I mean by there being more than one right answer, and too many variables. Somebody already posted, and I agree, that woodgrain is more common in early S-mint Lincolns. Why is this? In 1908 the San Francisco Mint introduced a newly discovered process of electrolytic refinery into the manufacture of copper coins. Perhaps there were start-up issues and process flaws that resulted in excess contaminants, or too much zinc in the resultant copper. Maybe that explains it, maybe not. It probably does not help to explain why an Indian Head Cent of the 1880s or a Lincoln Cent of the 1970s (posted) has woodgrain.
Some refer to overgraded slabs as Coffins. I like to think of them as Happy Coins.
Comments
Look on the thread : Dan Carr's Latest, pp#66 July 22 for his comments about "Orang Peel."
Nope. I'm requesting modern surface analysis, not something that is 50-year old hearsay.
It is similar unquestioning acceptance of "ancient revealed wisdom" that has been detrimental to numismatics for years. If he were alive Wally Breen would award you a "certificate of authenticity" - for a fee, of course. Simply because you or I make a claim of knowing the cause of "wood grain" does not make it a fact. There is no challenge - only a desire for all to know objective truth. Your assumption might be correct, but the "witnesses" wrote nothing and they are all dead.
Objectively, there is no right or wrong answer to the question; results of modern examination will reveal the answer.
The truth can be determined by modern nondestructive metallurgical analysis and professional data analysis.
For those who like the "look" of wood grain, the cause is probably of little importance and preservation of greater significance.
I disagree. The cause of the woodgrain effect is extremely important. Unfortunately,I forgot to check your book last night to see if it is addressed.
In the meantime, what you are requesting [**"I'm requesting modern surface analysis, not something that is 50-year old hearsay."] has already been done long ago by the Mint Laboratory. Those old dead guys are probably rolling over in their graves at this remark. Nevertheless, I'm also one who weighs the source and content of anything I read.
As I wrote, I'm sure you will stumble across records of their analysis some day in your research. Until then. you can believe that the "gold" color streaks and inclusions are actually impurities made of gold.
Nope. You continue to reject making decisions on facts, not hearsay and speculation. What is it you fear? Where does the emotional tension originate that obstructs open-minded investigation using the latest technology? You, 'insider2' must make that examination.
Enjoy your "fantasy facts" -
Oh my, please don't attack the messenger.
Your beef is with the Treasury Dept. conclusions. I cannot help you or I would tell you where to look. Fortunately, you are a much better researcher than I'll ever be. I do agree that this information SHOULD ALREADY BE in a book about the Mint and coin making or in a book on errors. Unfortunately, it never occurred to us to write about "woodies" in our old ANACS column. In hindsight, It would have been a great topic but at the time, there was no mystery as to their cause or composition. Sort of like writing about a coin struck on a clipped planchet. It seemed that virtually everybody knew about them and their cause when teaching Summer Seminar. While clips are mentioned in all the references about how coins are made - If I remember - "woodies" may not have been. If they were, the conclusion was they resulted from an improper alloy mixture. Based on what we learned at the Mint, that's also what we taught in class. I'll try to dig out some of my old books on the minting process and error coins to see if I can find something to quote.
AND...This is something I'll agree on: Just because "everybody knows" or something has "always" been considered to be 100% true and is previously published, settled info, does not exclude it from being questioned and tested. So go for it and best of luck. Perhaps a "Go-Fund-Me" page. I'll donate.
There's nothing to add, insider2. Rejecting empirical testing and data analysis is illogical and counterproductive.
People in "the business" ought to be queuing at the chance to make a discovery and be a leader in numismatic knowledge. But, all I've heard are trilling tree frogs in the humid summer night.
You paint a very poetic image.
While I agree completely with your post, no one needs to prove the earth is not the center of the universe anymore. Carry on...
I'm actually very surprised that some numismatist has not published results on the woodie and shellcase phenomena from a metallurgical analysis perspective. I would think it would be pretty easy to do if you have access to an XRF or similar machine. The result I saw on shellcase were fairly definitive, since those elements found are not supposed to be in the mix. Perhaps the woodies won't be so easy to analyze? If what we are talking about metallurgically is indeed a mixing variance compounded by rolling, then the difference between colors could be relatively small differences in composition of the same elements. We're talking mostly Cu, with a small amount of Sn and Zn, where the ratio of Sn and Zn are not completely controlled, only the sum of the two. Sn and Zn tone differently from each other, and both differently from Cu, but all 3 may be present in a sample. The analysis would need to be shallow to the surface, and would look for relative proportions of Cu/Sn/Zn. It seems within the capability of a decent XRF.
http://macrocoins.com
These coins are so cheap that I would take one with a large streak and start milling off the parts of the coin (the streak can run deeply into the surface) until I was left with a tiny sliver of "off-color" metal. Then, I'd melt it and do the analysis. I have an Indian cent with several large blocks of yellow metal - one is laminating from the surface.
Any thing could happen at the mint factory when they were doing all the preparations, Impurities could get rolled into the strip. Over the years, I've seen gold coins with silver streaks that were struck into the coin and not part of the alloy. I've seen Indian's and Lincoln's with the same thing. Struck thru errors don't look anything like a "woodie" when examined under magnification.
I am aware of tests conducted on gold coins, none on copper coins.
One thing that I am fairly certain of is that there is more than one "right" answer as to the cause of woodgrain toning. After studying how copper coins tone, and listening to the more science minded posters here over the years, I've learned that copper (bronze) is too unpredictable to be able to explain with precision the various looks and toning of copper coins. So nothing short of modern tests can provide an objective answer to woodgrain. I've also learned to distrust "common knowledge" in the numismatic world, or "numislore" as I call it. It pervades our hobby, and needs to be exorcized.
There are too many variables in the minting process to assume that improper alloy mix is the root cause in all cases. Woodgrain could possibly be caused by contaminants in the alloy, lubricant contamination in striking, contamination in the rolling or drawbench process, improper washing or pickling of planchets, improper rinsing or drying of planchets, etc.
Here is what I mean by there being more than one right answer, and too many variables. Somebody already posted, and I agree, that woodgrain is more common in early S-mint Lincolns. Why is this? In 1908 the San Francisco Mint introduced a newly discovered process of electrolytic refinery into the manufacture of copper coins. Perhaps there were start-up issues and process flaws that resulted in excess contaminants, or too much zinc in the resultant copper. Maybe that explains it, maybe not. It probably does not help to explain why an Indian Head Cent of the 1880s or a Lincoln Cent of the 1970s (posted) has woodgrain.