Some time ago I found what appears to be a 1990 (P) Lincoln cent with proof like detail but that is impaired from circulation. Last night I found 2 other 1990 cents that caught my eye one having a matte like finish and the other possibly being a DDOR both with far less detail than the first I found and held on to. Literally every coin I have found from 1990 has been half as finely struck as this one or far less even when in AU or MS grades. My images are not very sharp due to lightning but should suffice, I pray. Image two is the coin of uncertainty, third the suspected DDOR which I will likely post in full detail later, image one is the coin with the matte-like finish and some likely biological residue. I do not expect this to be a no S 1990 but had enough doubt to post these coins for review and comparison. Some believe that a proof coin is no longer a proof once circulated but this is simply untrue as the quality and number of strikes reaches far beyond a simple finishing technique in terms of the identity of a coin. Especially one damaged in circulation resulting in missing copper plating. Thanks for your help.
While this is a prime example you can see your coin is not a proof. Once circulated it is still a proof, as that is a method of manufacture and not a grade, but it becomes an impaired proof.
What makes for the middle coin to be so much more finely detailed and for the devices to be different than the other two. I have not found a single match in quality of strike to the 2nd image from 1990 after viewing thousands of 1990 P cents. I realise it is missing the plating and finishing it is the strike I call into question as it appears to have been struck multiple times thinning the devices and sharpening the detail of Lincoln's bust
The proof cents are struck with cameo devices, As Micheal posted. Yours (neither of them) are proof quality coins, Philly's and the first two are corroded, not toned.
Let's say you actually looked at "thousands" of 1990 cents. There were 6.8 Billion (with a B) 1990 cents minted in Philadelphia. If you looked at 1000 1990 cents (20 solid rolls), you looked at a little less than 0.2 parts per million (0.00002% if I kept the decimals under control). 0.2 parts per million is the equivalent to 1 second in just under 2 months. Now let's examine what needs to happen for a proof to enter circulation. 1990 Proof cents were issued in plastic cases. Someone would need to take that set, make a decision to break it open (probably beating it with a hammer), and spend the coins for face value. Why they wouldn't take the set intact to a coin shop and sell it for a few times more than the 91 cents in face value is beyond me, but impaired proofs are occasionally found in circulation, so it happens. In 1990, the mint issued 3.3 million proof sets. Out of those 3.3 million sets, how many were broken up and spent for face value? 100? 1000? 10,000? Can't be many According to PCGS, an estimated 200 No S proof cents are believed to exist. That's 0.006% of all 1990 proof sets had a No S Cent. So let's say 10,000 proof sets were broken up and spent (personally, I think that's high, but since I don't have any hard data, it will work for this example). 10,000 broken and spent sets x 0.006% sets with a No S Cent = 0.6! That means you would expect to find less than 1 No S Proof cent in circulation. Even if we round up, out of the 6.8 Billion 1990 cents put into circulation 1 would be a No S Proof. 1 out of 6.8 Billion I don't think you found it
The middle one is the one that most strongly self declares that it is not a No S proof. You see that raised ridge running from the shoulder up through the L and IN G? that is a form of die deterioration that forms in over used dies. now business strike cent dies are used for 1 to 1.5 million strikes and not all of them will show that deterioration. Proof dies are used for 3 to 4 thousand strikes. There is no way that deterioration would show up that soon, and if it did the die would be pulled LONG before the deterioration got that bad.
