@BryceM said:
I may have a different take on this than others, but I'm generally a STEM sort of guy by nature and by training. First, it might be instructive to consider that there might be more than one valid definition. The entire hobby of collecting coins is subjective by its very nature, and concrete definitions aren't always available.
For starters, consider the surface of a coin in terms of metallurgy, chemistry, and topography. Let's assume we start with a perfectly homogeneous silver-copper planchet of ideal dimensions, on-spec purity, and a perfectly centered, fully detailed strike by dies midway between new and ready to be retired.
On striking, the microscopic details and imperfections of the die are transferred very quickly, but very predictably to the surface of the planchet. Metal moves to fill the voids and recesses of the die. Movement is constrained by the collar. Flow is generally outward, away from the center and the eventual erosion of the die caused by metal movement of the planchet produces microscopic ridges we call flow lines or radial flow lines. The die affects the planchet but the countless parade of planchets also affect the die (thus, the die state). These microscopic die details are impressed on the coin. The interaction of light with these ridges results in the quality we call original mint luster. The instant the coin leaves the dies it is as original as it will ever be. From there, many forces will act on the coin to change it.
The metallurgy generally doesn't change, at least on the interior of the coin, but all sorts of chemical things start to happen immediately. The various microscopic regions of stress and strain at the surface give some areas different propensity to chemical activity than other areas. Small inclusions or areas of impurity in the metal will have vastly different chemical properties than other regions. Oils, acids, and any number of other chemicals from the minting process are already present on the surface of the coin and will start to work immediately. Due to the topography of the coin and the process of striking some areas will harbor more of these potential reactants than others (pull-away toning, etc). Additional contaminants will gradually migrate to the coin either through the air or by direct contact. The effect of these may be undetectable to the human eye for many years, but cumulatively, things are already in motion. This happens to every coin, but obviously the process happens more slowly for some than others depending on storage conditions. Metallic silver forms chemical ionic bonds with a host of anions delivered by the atmosphere or contact. The most important of these are sulfur compounds which result in an ever-accumulating layer of silver sulfide. Oils from a fingerprint will coat and protect some areas while the neighboring bare regions will react at the usual rate.
Physical contact can result in macroscopic changes (a big hit, rim ding, staple scratch, or reed marks). Less forceful contact first removes the very high points of the microscopic ridges, blunting them, gradually diminishing the luster and original surface topography. When done gradually, we call this wear. Eventually, at some undefined moment, the coin forever passes from the realm of uncirculated, to circulated. If an unlucky coin is forcefully traversed by a cloth or finger, small bits of silica and other abrasives from dust in the air will gouge out what we call hairlines.
So far, I don't think anything I've said should be too controversial.
In reality, no coin I've ever seen is actually original with the exception of the nickels the Denver Mint was making on the day I visited.
The trouble arises from our lousy definitions and accepted norms in the hobby. Some things are clearly not original (melted, treated with sandpaper, shot with a bullet, bent, flattened by a train). Some things are generally accepted as original - a coin existing in a relatively undisturbed, unmolested state in relationship to its peers...... no deliberate chemical treatments (dipping, primarily), but in reality THERE IS NO SET DEFINITION and no consensus statement by any governing body. We give an automatic pass to coins exhibiting attributes that have been associated with particular methods of storage (certain albums, Commemorative mailers, slab inserts, Mint packaging, etc). In reality, we only make associations - nobody really knows if the 58-D Franklin in my hand got its colors from Mint Set packaging or from a really expert "artist."
For me, the term "Plausibly Original" seems to be about as good as we can expect. How a person defines this for themselves is a product of every coin they've ever seen, every conversation they've ever shared, and everything they've ever read.
That's a well thought out post about originality @BryceM. Please allow me to simplify this post and add a personal touch: For me (using fluorescent light and my trusty Nikon stereo microscope at 7X), I know it when I see it.
BryceM's insights are certainly valid and could be extended deeply into the metallurgical consequences of sudden overpressure on crystal structure at various layers of a coin. For example William Chandler Roberts-Austen established that the relief surface of a struck gold coin was harder and more resilient than the body alloy. This meant it took longer for initial loss of metal due to abrasion to occur than for the same loss once a coin's original surface had been breached.
However, for practical use something like SanctionII's revised definition might be workable.
" 'Original skin' on a coin means that no one has intentionally altered any of the surfaces since the coin was struck."
Interesting and informative thread. I won't claim to be able to point out real original skin, let alone define it, but I do like the appearance of many of the coins displayed in this thread thus far.
I bought this VF35 because I liked how it looks but what says the thread... yes, no, why?
Perhaps the biggest problem is that many people think they can determine if a coin has original skin and the accurate grade of coins from poor quality pictures. Unfortunately many people are unable to do these things well with the coins in hand. In fact I know numismatists that have been around for 40 yers that are average graders at best.
Please share your opinion, which coins listed in my post do you believe are not even close to being original?
"72, 20, 78 , 77-S, 46, 41, 39-D, 49, 44, & 75."
Thank you
I wasn’t speaking of your coins. More so past threads that are asking for people to post “original coins” . The whole thread usually goes down hill in a hurry.
Hard to say true original skin for many circulated because as it circulated the surface friction would of removed most and built up yuk. It’s hard to tell on some. I do like dark on many coins.
Thanks for clarifying Boosibri, I agree that in "past threads that are asking for people to post “original coins” . The whole thread usually goes down hill in a hurry."
Comments
Great looking piece👍🏻
Thank you for sharing it with us.
You have some very nice pieces.
That's a well thought out post about originality @BryceM. Please allow me to simplify this post and add a personal touch: For me (using fluorescent light and my trusty Nikon stereo microscope at 7X), I know it when I see it.
I do love the “Post a coin with original surfaces” threads where 90% of coins posted aren’t even close being original
Latin American Collection
BryceM's insights are certainly valid and could be extended deeply into the metallurgical consequences of sudden overpressure on crystal structure at various layers of a coin. For example William Chandler Roberts-Austen established that the relief surface of a struck gold coin was harder and more resilient than the body alloy. This meant it took longer for initial loss of metal due to abrasion to occur than for the same loss once a coin's original surface had been breached.
However, for practical use something like SanctionII's revised definition might be workable.
" 'Original skin' on a coin means that no one has intentionally altered any of the surfaces since the coin was struck."
Boosibri,
Please share your opinion, which coins listed in my post do you believe are not even close to being original?
"72, 20, 78 , 77-S, 46, 41, 39-D, 49, 44, & 75."
Thank you
Interesting and informative thread. I won't claim to be able to point out real original skin, let alone define it, but I do like the appearance of many of the coins displayed in this thread thus far.
I bought this VF35 because I liked how it looks but what says the thread... yes, no, why?
Here's more Seated dollars.
A lot this is subjective. Of all the photos shown I'd vote at least 10 of them as "not original" skin.....though no doubt market acceptable.
Perhaps the biggest problem is that many people think they can determine if a coin has original skin and the accurate grade of coins from poor quality pictures. Unfortunately many people are unable to do these things well with the coins in hand. In fact I know numismatists that have been around for 40 yers that are average graders at best.
I wasn’t speaking of your coins. More so past threads that are asking for people to post “original coins” . The whole thread usually goes down hill in a hurry.
Latin American Collection
I always prefer original skin and will pay a premium for it, versus some bright shiny coin.
Here is one...
Hard to say true original skin for many circulated because as it circulated the surface friction would of removed most and built up yuk. It’s hard to tell on some. I do like dark on many coins.
Best place to buy !
Bronze Associate member
Thanks for clarifying Boosibri, I agree that in "past threads that are asking for people to post “original coins” . The whole thread usually goes down hill in a hurry."