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Moderator
 United States
95360 Posts |
thanks for this topic - I find it very interesting. May have to read mor about this moving forwards.
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Pillar of the Community
 United States
3330 Posts |
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thanks for this topic - I find it very interesting. May have to read mor about this moving forwards. I while back, I posted this. It is related if you want some more reference leads: https://goccf.com/t/485666 |
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Pillar of the Community
United States
2731 Posts |
Interesting, Pete..thanks for the detailed breakdown. I always assumed the Philly skew in errors and varieties was mainly due to the larger volume of coins minted there, but your data shows the discrepancy is way too large for production numbers alone to explain it.
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Pillar of the Community
United States
3330 Posts |
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Interesting, Pete..thanks for the detailed breakdown. I always assumed the Philly skew in errors and varieties was mainly due to the larger volume of coins minted there, but your data shows the discrepancy is way too large for production numbers alone to explain it. I know! I have found nothing else to explain the skew either. For example, improper annealing can cause decarburization of die steel, thus encouraging chips and cracks. I can find no significant difference in the annealing practices between the mints. |
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Pillar of the Community
United States
3330 Posts |
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Having looked at thousands of 2006-2025 nickel reverses per year for three years, I can spot a Denver nickel with extreme accuracy just by the surface features. They tend to have a mirror rather than a matte texture I have now received 2 other responses about the "shine" on coins from Denver. I would be interested in someone explaining in more detail exactly how that can happen. WHAT CAUSES A MIRROR AS OPPOSED TO A MATT FINISH? I know, intuitively, that die polishing might be behind it, but I don't understand precisely HOW? |
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Pillar of the Community
 United States
6483 Posts |
It could be a feature of the dies. Perhaps there is a difference in the final preparation. I thought I remembered reading that the mints would plate or otherwise prepare the die surfaces to harden them and extend striking life. One thing that I can state confidently is that Denver nickels have a specific surface deterioration pattern that is different from Philly. They are much more likely to develop the melted butter ghosts on lettering—especially reverse lettering—that moves towards the center. I have sometimes wondered if Denver just runs the dies longer, but that would not explain the visibly burnished (D) vs. matte (P) appearance of the nickel surfaces.
However, it is also possible that there are minor differences in planchet preparation between Philly and Denver. I do not recall anyone mentioning the visible difference on other denominations. I will retrieve a few specimens from my weekly CRH that show the pattern.
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Pillar of the Community
United States
3330 Posts |
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It could be a feature of the dies. Perhaps there is a difference in the final preparation. I thought I remembered reading that the mints would plate or otherwise prepare the die surfaces to harden them and extend striking life. One thing that I can state confidently is that Denver nickels have a specific surface deterioration pattern that is different from Philly. They are much more likely to develop the melted butter ghosts on lettering—especially reverse lettering—that moves towards the center. I have sometimes wondered if Denver just runs the dies longer, but that would not explain the visibly burnished (D) vs. matte (P) appearance of the nickel surfaces.
However, it is also possible that there are minor differences in planchet preparation between Philly and Denver. I do not recall anyone mentioning the visible difference on other denominations. I will retrieve a few specimens from my weekly CRH that show the pattern. The mint has used PVD for numismatic {Proof} coin dies. In 2024, it was reported that "A project is underway at the Denver Mint to install a turnkey cleaning line and PVD coating system for the first time to coat work hubs with low CoF Chromium Nitride coatings." for Circulating Coins, 2024 Biennial Report, Page 8 PVD = Physical vapor deposition is a vacuum deposition method involving plasma sputter bombardment of target material to deposit thin films of that material onto surfaces (i.e., coining dies). PVD coatings are generally used to improve hardness and wear resistance. |
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Pillar of the Community
United States
8740 Posts |
Another great article, Pete. Thank you!
-makecents-
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Pillar of the Community
United States
3330 Posts |
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Another great article, Pete. Thank you! THANK YOU! I appreciate your support and encouragement! |
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Pillar of the Community
United States
8740 Posts |
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I do not recall anyone mentioning the visible difference on other denominations. I have not paid as much attention to the surfaces as I have the devices between the two mints. I have noticed that on the Denver later memorials and also the shield cents appear to have a softness to all the devices that make them look thicker, almost as if they have a slight spread. -makecents-
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Pillar of the Community
United States
676 Posts |
Thanks for the article, wasn't something that I had thought about.  |
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Pillar of the Community
United States
6483 Posts |
Denver notably has had some visible planchet differences to Philly over the years. Nickels from 2000 are notable for a polished gleam. Folks here (including myself) have posted a number of mirror finished Denver coins over the past few years. I had assumed that was a planchet difference, but I've never read a pro confirmation or refutation of that observation.
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Pillar of the Community
United States
6483 Posts |
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I have noticed that on the Denver later memorials and also the shield cents appear to have a softness to all the devices that make them look thicker, almost as if they have a slight spread. Agreed. I immediately know that when I see that chrome-like gleam and softened features on a nickel reverse, it's a Denver minted coin. Not all Denver coins are guaranteed to have that finish, but I don't remember seeing a similar Philly coin. |
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Pillar of the Community
United States
6483 Posts |
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Pillar of the Community
United States
3330 Posts |
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you can see that melted butter beginning atop FIVE CENTS. Thanks. I understand now. I have seen that and did not know whether I was seeing reflection or Die Deterioration! I guess I still don't understand! |
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Replies: 21 / Views: 520 |
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Posted 05/01/2026 3:55 pm
