Silver Eagle 25th Ann Set coin finishes?

I know the US Mint claims the UNC versions all have different finishes...but they are all completely identical...essentiall matte proofs. Any feedback here? The reverse proof looks like the finish was done after striking for the frosted part...like the ATB direct sale Quarters. Has anyone found any visual difference between the San Fran struck AE Bullion and the West Point Struck AE bullion?

 

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This is how the US mint explains it. I see a slight difference.

"The term "uncirculated" refers to the specialized minting process used to create these coins. Although they are similar in appearance to American Eagle Bullion Coins, these new uncirculated coins are distinguished by the presence of a mint mark, indicating their production facility, and by the use of burnished coin blanks, which are hand-fed into specially-adapted coining presses one at a time."http://www.usmint.gov/mint_programs/american_eagles/index.cfm?action=AmEagUnc

 

They can't be uncirculated and proofs. Those are two different manufacturing process' using two entirely different planchets. The uncirculated coins are struck on burnished planchets, and the proofs are struck on proof planchets that go through an entirely different process than the burnished planchets.

 

With some US Mint commems though it is clear they essentially took the same care in preparing the dies/blanks for the proofs as they did the uncirculated coins. World mints even call these matte proofs.

 

As a side note..I can see visual differences in the edge/border on S eagles vs W eagles.

 

And they conveniently forget to tell you that ALL planchets are burnished after annealing and before striking. The "Unc with mintmark" versions are whiter and frostier than the bullion versions not because the "Unc" has been struck on a burnished planchet, but because something has been done to the dies. A different or heavier etching. They just aren't telling us. and claiming it is a difference in the planchet.

Striking by the dies flattens or wipes out differences or irregularities in the planchet so a regular planchet or an etched planchet when struck by the same dies would both have nearly the same appearance. But a regular planchet struck by normal dies will look much different from a regular planchet struck by etched dies. It is the DIES that are the overwhelming factor in the appearance of the final coin.

 

Just from looking at my coins it seems as though the 2011 UNC(bullion strike) have the field and lady liberty showing the same finish that all ASE's have shown since 1986. As does the 2011 west point 25th anniversary eagle. My (S) San Fran strike without mint mark the field is the same as the west point but the lady liberty has more of a polished finish. I would not go so far as to say that it's a reverse proof polishing but it has more of that type of look than the west point coins. Now the 2011 W from the 25th anniversary set seems to have the same finish as the 2011 west point. That's kind of odd because when you look at 06,07,and 08 W burnisheds the polishing is so pronounced they actually look frosted and thus duller than a bullion strike ASE. The S mint 25th anniversary coin has the high polish on lady liberty from the san fran (S) coins but also has a highly polished field to match. The proof 25th anniversary coin is a typical proof eagle same as from the beginning of the proof ASE's. Finally the reverse proof has the dull looking frosting (like the burnished W coins of 06,07,and08) in the field and a super high polished mirrored proof finish on lady liberty. So there are/can be slight differences with the dies so they aren't really lying however as with all coins earlier struck coins from fresh dies look crisper and more beautiful than those struck just before a die is retired. Look at my coins my West point burnished looks very close to the west point regular bullion strike.

 

Still, US Mint uses the term UNC loosely. Coins in bags and UNC commems are produced using entirely different processes. With many commems and I believe with some of the Silver Eagles...the blanks for proof and UNC are the exact same blanks. Both dies are prepared with the same care...except the UNC version is essentially a Matte Proof...where the entire surface is blasted...not just the raised relief. The US Mint has started polishing the raised areas of proof dies with a laser which eliminates the need to mask out the rest of the die. The laser gives the frost that sparkling look like on the reverse proof. The UNC dies used for commems and eagles which aren't bullion quality are proof dies that are frosted over completely but not using the laser technique. The US Mint also has used the term Matte for some recent special issues as well.

Look at a Chinese Panda...the UNC version is very much proof-like as well.

 

To get that smooth UNC look on some of the eagle the dies still have to be polished and then buffed. You don't just use the same quality die as for a circulating penny. Matte Proof is a finish used by many mints.

 

Yes I meant etched with a laser for the devices. But they do use a diamond polisher to get the mirror finish. In some cases the polish the entire die with a diamond polisher...then mask the polished areas and cut out the devises...then they etch the devices. I think the laser eliminates the need for the masking. I have seen the entire process from start to finish at The Franklin Mint before they stopped minting in 2002. Their proof minting was as good as anything out there so they know what to do. But they used old equipment not laser.

 

UNC dies for the commems etc are definitely frosted after being polished to a smooth finish...though not laser etched. I would expect it to be the same technique that frosted the devices on a proof coin before the laser etching came about. Thats what gives the coin the frosty rich surface. Its the same as a Matte Proof. The ATB UNC coins were an odd product that was frosted after being struck. IMO the bullion ATB coins look better.

 

US Mint bought a ton of equipment from FM in the 80's. The ATB coins sold direct from the mint are vapor blasted after being struck. That info was provided by the mint. The others no, no post strike treatment, but the blanks are cleaned and polished in tumblers. Perth Mint supplies blanks to US Mint as does Sunshine Mint.

 

From Coin World: "New equipment the U.S. Mint ordered to produce the post-strike vapor-blast finish applied to Uncirculated America the Beautiful 5-ounce silver coins likely will be able to resolve the inconsistency in the finish being reported for 2010-P coins, U.S. Mint spokesman Michael White said July 27."

 

Yes thats what I meant. My comments on the ASE and modern commems implied that UNC and Proof both received special die treatments...but UNC and proof are probably struck on the same polished blanks. In some cases, the UNC is really a matte proof. The dies being polished to proof quality then treated with a matte finish on the die.

Just to note...I find coin production a very interesting topic and love the discussion here. I am one who collects all types of coins for the beauty and not for investment.