<< <i>I believe most people who know what they're looking at with regards to toned coins can just glance at a coin and make a AT/NT determination in a couple of seconds in most cases. >>
This is most certainly true BUT...what if someone who has been collecting since, say, 1995 tries this. And let's say that many so-called AT coins are getting into legit slabs since then. Based on this how is one going to determine if a coin is NT based on the "known material" as Rob put it? If many coins are being put into holders as "market acceptable" then how is someone that is not an old-time going to know the difference? Interesting question I think....
<< <i>I believe most people who know what they're looking at with regards to toned coins can just glance at a coin and make a AT/NT determination in a couple of seconds in most cases. >>
This is most certainly true BUT...what if someone who has been collecting since, say, 1995 tries this. And let's say that many so-called AT coins are getting into legit slabs since then. Based on this how is one going to determine if a coin is NT based on the "known material" as Rob put it? If many coins are being put into holders as "market acceptable" then how is someone that is not an old-time going to know the difference? Interesting question I think....
jom >>
There are quite a few of us "old timers" who have explained in great detail what to look for. While a new collector won't be able to learn from experience because of all the "market acceptable" junk floating around, he can learn by listening to the advice of those of us who collected in the dark age before certification services.
I'm sure they can but there are TWO problems I see with this.
1) Not all old-timers are fluent in all coins series to really know the difference. What may appear to be an AT Morgan may very well be NT for some other coin.
2) You simply cannot learn how to do this by someone TELLING you what to look for. You need to SEE it yourself. Today, IMO, that is increasingly difficult.
I second all the kudos for this scholarly written thread. I offer a few clarifications.
First, it may be technically accurate to say that toning continues after the coin is removed from the source of the oxidation. However, in my experience the rate of such toning is usually so minute as to be invisible to the eye over an extended period.
Next, it is a little misleading to say that not all toned coins will turn black. If properly stored, there is no reason for a toned coin to turn black at all and no more so than it is for a white coin -- perhaps less so. I have owned many toned pieces for over 30 years, and they have remained unchanged as best I can tell for all that time.
Finally, it seems to me the coin pictured in the subject thread is clearly not AT as opined by the author. Assuming I'm "correct," or at least supported by the toning experts here, I would find that result just a little ironic, given the impressive display of academic knowledge that the author has dispensed.
I suppose one lesson here is that successfully putting any theory into practice typically requires extensive real world experience in addition to an understanding of the underlying conceptual relationships.
This is a Wonderful thread - lots of informative knowledge - this paragraph should be kept on everone's desk if you collect toned coins:
<< <i>Besides, if a coin exhibits the correct color progression or not has little to do with it's being NT or AT, the color progression is a result of the thin film and is indifferent to it being NT or AT. >>
This thread has so much great information that I've book marked it for future reference.
Collecting eye-appealing Proof and MS Indian Head Cents, 1858 Flying Eagle and IHC patterns and beautiful toned coins.
“It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.” Mark Twain Newmismatist
Accented by TomB's "One thing that everyone should keep in mind is that while toning is based upon science, it is not a completely controlled reaction and, as such, is not perfectly predictable" this is the best post I've read here in the past year. TTT
There are some names here that haven't been around since T-Rex disappeared. Kinda sad to think some of these people aren't sharing valuable information with us any more.
yeah, great post, but I have a quick question, I have a morgan much like the one posted by dizzyfoxx,.....and on the reverse at the outside of most of the letters on the outermost edges it looks much like a die crack error ,as the line goes most of the way around...is this most likely the edges of the layering of the films discussed here?.......
Well, it's been a while since I've done anything with this post so I decided to add a little more here...
Above is a pic of a star on a naturally toned Morgan Dollar. It shows the common shadow effect due to the atomic restructuring of the metal alloy due to excessive pressure from the striking of the coin.
The interesting thing is the toned line that runs out from the tip of the star from the 7 o'clock position. If your look closely, you will notice that the very tip of that star has die wear on it, somewhat visible from the flow lines running out from where the tip of the star touches the field. This natural die wear causes the metal to flow smoothly into the field in a way where the metal experiences less pressure than metal in the areas of the star that are perpendicular or squared off with the fields.
These squared off areas (like the arms of the star where the contact between the star and field are sharp - perhaps from a fresh die polish) cause the metal to undergo increased pressures and are enough to change the metal's atomic structure to become toning resistant. See how the toning looks all stretched out from the strike? Even though the toning occurred many years after the coin was struck.
Here's a great site about thin films and optical colors... it's a little geeky and technical but lots of interesting info there:
<< <i>yeah, great post, but I have a quick question, I have a morgan much like the one posted by dizzyfoxx,.....and on the reverse at the outside of most of the letters on the outermost edges it looks much like a die crack error ,as the line goes most of the way around...is this most likely the edges of the layering of the films discussed here?....... >>
"Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you." -Luke 11:9
"Hear, O Israel: The LORD our God is one LORD: And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might." -Deut. 6:4-5
"For the LORD is our judge, the LORD is our lawgiver, the LORD is our king; He will save us." -Isaiah 33:22
Comments
<< <i>I believe most people who know what they're looking at with regards to toned coins can just glance at a coin and make a AT/NT determination in a couple of seconds in most cases. >>
This is most certainly true BUT...what if someone who has been collecting since, say, 1995 tries this. And let's say that many so-called AT coins are getting into legit slabs since then. Based on this how is one going to determine if a coin is NT based on the "known material" as Rob put it? If many coins are being put into holders as "market acceptable" then how is someone that is not an old-time going to know the difference? Interesting question I think....
jom
<< <i>
<< <i>I believe most people who know what they're looking at with regards to toned coins can just glance at a coin and make a AT/NT determination in a couple of seconds in most cases. >>
This is most certainly true BUT...what if someone who has been collecting since, say, 1995 tries this. And let's say that many so-called AT coins are getting into legit slabs since then. Based on this how is one going to determine if a coin is NT based on the "known material" as Rob put it? If many coins are being put into holders as "market acceptable" then how is someone that is not an old-time going to know the difference? Interesting question I think....
jom >>
There are quite a few of us "old timers" who have explained in great detail what to look for. While a new collector won't be able to learn from experience because of all the "market acceptable" junk floating around, he can learn by listening to the advice of those of us who collected in the dark age before certification services.
1) Not all old-timers are fluent in all coins series to really know the difference. What may appear to be an AT Morgan may very well be NT for some other coin.
2) You simply cannot learn how to do this by someone TELLING you what to look for. You need to SEE it yourself. Today, IMO, that is increasingly difficult.
jom
First, it may be technically accurate to say that toning continues after the coin is removed from the source of the oxidation. However, in my experience the rate of such toning is usually so minute as to be invisible to the eye over an extended period.
Next, it is a little misleading to say that not all toned coins will turn black. If properly stored, there is no reason for a toned coin to turn black at all and no more so than it is for a white coin -- perhaps less so. I have owned many toned pieces for over 30 years, and they have remained unchanged as best I can tell for all that time.
Finally, it seems to me the coin pictured in the subject thread is clearly not AT as opined by the author. Assuming I'm "correct," or at least supported by the toning experts here, I would find that result just a little ironic, given the impressive display of academic knowledge that the author has dispensed.
I suppose one lesson here is that successfully putting any theory into practice typically requires extensive real world experience in addition to an understanding of the underlying conceptual relationships.
My memory is usually pretty good.
Yup found the whole image.........
<< <i>Besides, if a coin exhibits the correct color progression or not has little to do with it's being NT or AT, the color progression is a result of the thin film and is indifferent to it being NT or AT. >>
This thread has so much great information that I've book marked it for future reference.
“It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so.” Mark Twain
Newmismatist
Come on over ... to The Dark Side!
Hoot
Apropos of the coin posse/aka caca: "The longer he spoke of his honor, the tighter I held to my purse."
--------T O M---------
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Absolutely, positively, and without a doubt a superlative thread!!! Thanks merysu & pharmer for pointing it out.
Oh, I might as well throw a toned coin on the thread...
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Apropos of the coin posse/aka caca: "The longer he spoke of his honor, the tighter I held to my purse."
I've been told I tolerate fools poorly...that may explain things if I have a problem with you. Current ebay items - Nothing at the moment
There are some names here that haven't been around since T-Rex disappeared. Kinda sad to think some of these people aren't sharing valuable information with us any more.
Above is a pic of a star on a naturally toned Morgan Dollar. It shows the common shadow effect due to the atomic restructuring of the metal alloy due to excessive pressure from the striking of the coin.
The interesting thing is the toned line that runs out from the tip of the star from the 7 o'clock position. If your look closely, you will notice that the very tip of that star has die wear on it, somewhat visible from the flow lines running out from where the tip of the star touches the field. This natural die wear causes the metal to flow smoothly into the field in a way where the metal experiences less pressure than metal in the areas of the star that are perpendicular or squared off with the fields.
These squared off areas (like the arms of the star where the contact between the star and field are sharp - perhaps from a fresh die polish) cause the metal to undergo increased pressures and are enough to change the metal's atomic structure to become toning resistant. See how the toning looks all stretched out from the strike? Even though the toning occurred many years after the coin was struck.
Here's a great site about thin films and optical colors... it's a little geeky and technical but lots of interesting info there:
Understanding Interference Patterns in Soap Films
.
<< <i>yeah, great post, but I have a quick question, I have a morgan much like the one posted by dizzyfoxx,.....and on the reverse at the outside of most of the letters on the outermost edges it looks much like a die crack error ,as the line goes most of the way around...is this most likely the edges of the layering of the films discussed here?....... >>
Not sure what you're describing, pics would help.
Very Scholarly Thread and the best I have enjoyed in a while...
-JZ
https://www.pcgs.com/setregistry/quarters/washington-quarters-major-sets/washington-quarters-date-set-circulation-strikes-1932-present/publishedset/209923
https://www.pcgs.com/setregistry/quarters/washington-quarters-major-sets/washington-quarters-date-set-circulation-strikes-1932-present/album/209923
"Bongo hurtles along the rain soaked highway of life on underinflated bald retread tires."
~Wayne
"Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you." -Luke 11:9
"Hear, O Israel: The LORD our God is one LORD: And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might." -Deut. 6:4-5
"For the LORD is our judge, the LORD is our lawgiver, the LORD is our king; He will save us." -Isaiah 33:22
There are many others, by Cardinal, TomT, Conder101 etc...
Too bad there isn't an archive forum to find these all in.
good job rob
Go BIG or GO HOME. ©Bill
Apropos of the coin posse/aka caca: "The longer he spoke of his honor, the tighter I held to my purse."
Apropos of the coin posse/aka caca: "The longer he spoke of his honor, the tighter I held to my purse."
everyone should bookmark this thread to refer back to when these type of questions come up
8 Reales Madness Collection
Apropos of the coin posse/aka caca: "The longer he spoke of his honor, the tighter I held to my purse."
<< <i>Thought with all the new members lately, they might enjoy one of the best threads ever on this forum. Want to understand toning? Here you go. >>
Good one to bring to the top.