It's just an older A&D, similar to this one. http://balance.balances.com/scales/42 The 0.00001 g resolution balances are standard fare in any analytical lab. One lab I worked in had 8 of them. We have a TGA (TA Q5000) in our lab too. Off the top of my head, the balance built into that has 0.000001g resolution. I believe BOTH are true. Metal definitely gets pushed around and metal definitely gets removed during wear.
It's pretty simple for just about anybody with a halfway decent scale to see it for themselves. All ya have to do is weigh coins and know what the tolerances are - which can be found in the Coin World Almanac. So go weigh some coins in XF, VF, F, VG, G and see for yourself - I have. But what you're gonna find out is that until you get to VG and lower coins, the coin will be within mint tolerance.
This was a good question with a very simple answer: YES! Nevertheless, we got so far away from that simple answer by introducing things that are not helpful. For example: The government says a $20 Liberty should weigh 33.436 grams +/- .032. SO WHAT! Some genuine coins come right off the press below weight (out of tolerance). Therefore, trying to equate a coin's weight with its condition is ..... Doug posted: "Books is telling you - 'wear can cause the loss of metal.' Well, the key word in that sentence is CAN, and I suspect Books worded it that way quite intentionally. And he is also quite correct - it "can" cause a loss of metal. But that is not the same thing as saying - it does cause a loss of metal." So I'll say it: Friction wear is just that. Abrasive friction to a coin's surface that removes metal. Wear causes a loss of metal. Problem is, the loss of metal happens on a level that is generally not noticeable until it is. Then we see a change in the original surface. We are talking microns at first. Lightly rub a nail file on the rim of a circulated gold coin. What do you see? Microscopic particles of gold metal that has been removed from the coin. "Here's the explanation. With almost any coin, regardless of composition or type, the first and middle stages of wear DO NOT cause a loss of metal. It is only when coins are worn to the point of VG grade, and often not until they have reached G grade, or lower that they lose enough metal due to wear to take the coins out of mint tolerance." ALL WEAR causes loss of metal. You can see the loss when a coin goes from Mint state to AU-59.999. "What you have to understand is this. When a coin is made it has a given weight that has been established by design. And there is a tolerance for that weight, a range if you will. That tolerance range differs with each coin type, but each one has its own. As a rough rule of thumb that tolerance is about 1%. So when brand new and freshly minted every coin of a given type will weigh within 1%, plus or minus, of its design specified weight. What that means is you can take a coin that is fairly graded at F, weigh that coin, and it will be within 1% of its original design weight. In other words it will not have lost any weight, at least not that can be proven because of the tolerance range." As I wrote above, forget about a coin's weight. Due to the tolerances of a machine shop (the U.S. Mint) some XF+/AU Morgan's may weight more than an Unc! "And it's that line of thinking that usually gets most people. What they don't take into account is that wear doesn't remove metal from the coin until it reaches very advanced stages. Prior to that it's more a matter of the metal being pushed down, squished, flattened out - but remaining on the coin." I'll give you this one. Crush a coin in a massive press and much of the design will be lost and virtually all of the coin's original metal will still be present. Unfortunately, this type of damage is NOT CONSIDERED TO BE WEAR. When the weight of that coin dropped by 0.000001, I'll argue that some metal was lost. "It's pretty simple for just about anybody with a halfway decent scale to see it for themselves. All ya have to do is weigh coins and know what the tolerances are - which can be found in the Coin World Almanac. So go weigh some coins in XF, VF, F, VG, G and see for yourself - I have. But what you're gonna find out is that until you get to VG and lower coins, the coin will be within mint tolerance." Which has nothing to do with how much metal was removed by friction wear.
Yeah, I'd like to see one of these very sensitive scientific instruments. Must be very cool to have access to one when weighing coins. Does wear remove metal or "push it in"? Hmm. "Pushing in" is perhaps what happens when coins bang against each other (contact marks), right? But does wear compact (push in) metal? An interesting question...
And I never said that "some", stress some, metal wasn't lost. On the contrary, it has everything to do with it ! Let's put things into their proper perspective. For example, you listed the tolerance for a double eagle to be +/- .032 gm. Do you know how much that is ? It is one half of one grain - 1 grain = 0.06479891 gram. And the specified weight of the entire coin was 516 grains, or 33.436 grams. So what we're talking about here is that the tolerance level for the coin is one tenth of one percent. Now you claimed above that some coins came off the press out of tolerance. I won't doubt your word but I've certainly never seen one that was, and I've weighed more than a few of them. But let's assume some were, let's double it even. That would still mean that it was only 2 tenths of 1 percent. Even if you multiplied it by 10 to get to 1 percent it would still only be 0.320 gm ! And I won't believe for a second that any coin was off ten times its tolerance level. But the simple fact remains, the coin I used as an example in this thread was weighed when it was brand new, and when it had reached the stage of wear that you see in the pictures. So whether it was within tolerance or not, has absolutely nothing to do with anything. Because the before and after weight of the coin only changed by 0.003 grams. That's how much metal was lost by friction wear, and that's 1/10 of 1/10 of one percent ! So does some metal wear away, leave the coin ? Absolutely yes ! But when you're talking about amounts THAT small, that's when you say SO WHAT !
GDJMSP, posted: "So does some metal wear away, leave the coin ? Absolutely yes!" That's my point and you have just answered the OP's question. You did it with two words, I did it with one. I prefer your answer. "But when you're talking about amounts THAT small, that's when you say SO WHAT!" I hope you'll agree that the "so what amount" of metal lost does not change your answer - Absolutely yes. Additionally, the "so what amount" is enough to (technically) make an original Mint State coin an About Uncirculated for dinosaurs like you and me.
And no one disputes that. Nor did anyone ever dispute that "some" metal did leave the coin due to wear. But the point that needed to be made, and understood, is that wear, until it reaches the extreme stages, removes so little metal as to not even matter. In past threads on this same subject people have guessed that coin in VF and even XF might have lost 10% or more of their specified weight, let along the coins that are in the F range. When the truth of the matter is coins only lose a tiny, tiny, fraction of that amount of weight due to wear.
TPGS do not grade coins by weight. As to this statement of yours concerning what matters: "But the point that needed to be made, and understood, is that wear, until it reaches the extreme stages, removes so little metal as to not even matter." I think it can easily be refuted by a few extreme examples from the marketplace. AU $470 MS60 $2200 AU $21,000 MS60 $120,000 AU $940 MS60 $12,500 AU $1500 MS60 $37,500 Since I (and the coin market) don't consider the amount of metal lost between an AU-55 and an MS-60 to be an "extreme stage," this subject is just another thing we'll disagree on.
Morgan silver dollars are supposed to weigh around 26.73 gm. My grandmother lived near Reno and pulled these worn specimens out of circulation in the 1960's along with many others. They no doubt were used at the casinos there. I graded them using the Redbook grades. United States Dollar 1896-O Very Fine 26.20 gm 98% of normal United States Dollar 1897-O Fine 25.94 gm 97% of normal
The problem is that 26.73 is the nominal weight, but the tolerance is +/- 0.097 gram, so a fresh Morgan could have been anywhere in a range of 26.83 (significant ) to 26.63 grams. To say how much weight loss occurs with different degree of wear, you have to know the weight of each sample when minted , and then using the graded weight , determine the percentage of loss. I set up an experiment a year ago with 5 mint 1959 Lincolns, all had varying initial weight measured on a lab scale, but it became static as I could not decide on a mechanism to produce identical wear to a grade point before weighing the weight loss. I has some worn diamond laps ( flat rotating grinding surfaces I use for gemstone faceting, so I tried one) .However , as many would guess, the wear pattern and the weight reduction is not the same pattern as a cent worn in circulation ( much more of the rim is worn off when flat ). So now I am deciding how to construct a " pant pocket wear" device, using the lap with a dense wax layer with a gentle convex curve, covered with a 'denim' surface and coated with diamond dust. I need to rework the wax layer to produce a normal wear pattern on the cent and then run a series of wear. Anyone else wants to run with this ~ go for it, I have plenty other things to do. Jim
P.S. The reason I don't just place them in my pocket and have them wear normally, is that many of us would not last beyond EF, let alone G4.
I read somewhere decades ago that someone proposed a grading scale based on a coin's weight. Obviously, the idea died long ago. IMO and that of those with more clout, it cannot be done in any practical way so why even bring it up. We don't know the original starting point when each coin left the press!
Well we could do it to 1oz AGEs, they must have higher tolerances, right . If someone sends me 10, I will start right away.
Ehhh, maybe. But that AGE only took 7 years, and I carried that specific one longer than any of its predecessors. And Kentucky, there were only 4 of them in total, not 10. As best as I can recall the shortest time for any was about a year, the other 2 several years each. And there was a constant, of sorts anyway, involved. For 40 + years I always carried a pocket knife and 4 quarters in my right front pocket. (Which is also where I carried the AGEs.) Over the course of a normal day I would additional pocket change as it was accumulated. But the next morning it was back to the norm - every day, it still is. In addition to that whenever a situation came about that required a coin flip to determine an outcome, and with me given my nature that happened a lot, the AGE would come out it was the coin flipped. Sometimes it would land on the ground, the floor, a table, my hand etc. The point I'm making is that it wasn't babied or handled with any degree of care. It was treated as an ordinary coin would be. It was the same with all of them. And in my estimation the degree of wear was always roughly the same at the various time points. The point of all this is this Jim - it could be done Maybe not by you or me, but it could be done.
That would be Weimar White. I read his articles on the subject. When he tried to do it for circulated coins his results were all over the map and when he tried to use it for telling MS from AU he didn't take the tolerance into account. The only way his plan would work was if you knew the exact weight of the coin when it came out of the press. So naturally the idea was unworkable.
