Tweet
I discovered this mystery coin in a machined rolled box of pennies from the bank. My first impression, when I found the 1979D cent (see attachments), was that it was a split planchet error.
However, because this 1979D penny weighed in at 2.87 grams, I determined it was too heavy to be this type of error. Next, I considered the possibility it was a uniface rolled-thin planchet error. While highly unlikely, I found this coin does exhibit a fine proto-rim (see attachment) on its blank reverse and a slight bevel (see fourth attachment with image of top portion of edge, towards reverse side, showing this fine beveling as a dark line). The fine reverse proto-rim and beveling would seem to discount that this cent had its reverse device and design defaced by having been tooled/machined down after it left the mint; otherwise, there would be no proto-rim extending over the edge of this cent to its blank reverse side.
I next considered the possibility this odd coin was a mint-made experimental cent meant to test pure copper plated only to the rims and edge of an underlying brass planchet (due to yellow brassy appearance). The reason I think the rims and edge are plated in pure copper is because they both appear peach/pink-like in color -- which is the correct color appearance for untarnished pure copper (see attachments). The process that may have been used for plating the suspected pure copper on this coin may have been "brush plating" or some other unknown process. For comparison purposes, I found online a similar coin for your review -- the 1989 Canadian $1 Mackenzie River commemorative coin which is described as being composed of silver with a copper rim.
There are obviously some caveats with respect to this coin being an experimental coin. First, the mint has denied that plating experiments took place with respect to the development of the post-1981 copper plated zinc penny. However, the Mint has been less than forthcoming with respect to revealing its experimental secrets and, even, general Mint processes --the 1974 bronze cladded steel cent struck on regular Lincoln dies is a case in point. Second, there are scratches over the reverse face of the 1973D cent that appear to be tooling marks -- the final question is whether these marks were created at the mint or post-mint.
If this is an experimental coin, I believe one possibility for these tooling marks is that they are the result of the Mint creating an experimental planchet on the cheap. Based on this theory, instead of making nonsense dies (which is a time consuming process), the Mint may have created this odd coin by tooling down the blank before it was put through the upset mill; thereby reducing its weight so if it ever were inadvertently released by the Mint, no one would suspect it was an experimental coin. The fine reverse proto-rim on this cent overlaps these marks. Therefore, the apparent tooling marks on the 1979D cent would have been placed on the blank before it went through the upset mill and before it was finally struck as a planchet in the coining press.
Next to muddy the waters, the Mint may have then struck this underweight planchet by unconventionally placing two planchets in the coining press' collar at the same time, while lowering the standard pressure normally used for striking (based on obverse design elements on 1979D cent appearing to have been weakly struck). Under this scenario, two uniface struck coins would have been created -- one with the obverse image from the hammer die and one with the reverse image from the anvil die. I may have discovered the uniface struck obverse of this 1979D cent. Similar to the Mint creating an underweight planchet by tooling this coin, the Mint may have performed the foregoing unconventional minting procedure to obscure that it had created an experimental cent in case it were ever to be inadvertently released into circulation.
As a side note, this coin appears to have been improperly annealed as there is pitting that can be clearly seen on its reverse, rims and edge.
Finally, it is also possible this coin is the result of a post-mint alteration. I do not know, however, why anybody would create such a time-consuming alteration (or even have the means to do it outside a mint) and then place it into general circulation -- just for fun.
In my opinion, this is truly a great numismatic brain teaser. If any of you have any advice on this oddball 1973D cent, I would welcome your comments. Thanks for your assistance in advance.
However, because this 1979D penny weighed in at 2.87 grams, I determined it was too heavy to be this type of error. Next, I considered the possibility it was a uniface rolled-thin planchet error. While highly unlikely, I found this coin does exhibit a fine proto-rim (see attachment) on its blank reverse and a slight bevel (see fourth attachment with image of top portion of edge, towards reverse side, showing this fine beveling as a dark line). The fine reverse proto-rim and beveling would seem to discount that this cent had its reverse device and design defaced by having been tooled/machined down after it left the mint; otherwise, there would be no proto-rim extending over the edge of this cent to its blank reverse side.
I next considered the possibility this odd coin was a mint-made experimental cent meant to test pure copper plated only to the rims and edge of an underlying brass planchet (due to yellow brassy appearance). The reason I think the rims and edge are plated in pure copper is because they both appear peach/pink-like in color -- which is the correct color appearance for untarnished pure copper (see attachments). The process that may have been used for plating the suspected pure copper on this coin may have been "brush plating" or some other unknown process. For comparison purposes, I found online a similar coin for your review -- the 1989 Canadian $1 Mackenzie River commemorative coin which is described as being composed of silver with a copper rim.
There are obviously some caveats with respect to this coin being an experimental coin. First, the mint has denied that plating experiments took place with respect to the development of the post-1981 copper plated zinc penny. However, the Mint has been less than forthcoming with respect to revealing its experimental secrets and, even, general Mint processes --the 1974 bronze cladded steel cent struck on regular Lincoln dies is a case in point. Second, there are scratches over the reverse face of the 1973D cent that appear to be tooling marks -- the final question is whether these marks were created at the mint or post-mint.
If this is an experimental coin, I believe one possibility for these tooling marks is that they are the result of the Mint creating an experimental planchet on the cheap. Based on this theory, instead of making nonsense dies (which is a time consuming process), the Mint may have created this odd coin by tooling down the blank before it was put through the upset mill; thereby reducing its weight so if it ever were inadvertently released by the Mint, no one would suspect it was an experimental coin. The fine reverse proto-rim on this cent overlaps these marks. Therefore, the apparent tooling marks on the 1979D cent would have been placed on the blank before it went through the upset mill and before it was finally struck as a planchet in the coining press.
Next to muddy the waters, the Mint may have then struck this underweight planchet by unconventionally placing two planchets in the coining press' collar at the same time, while lowering the standard pressure normally used for striking (based on obverse design elements on 1979D cent appearing to have been weakly struck). Under this scenario, two uniface struck coins would have been created -- one with the obverse image from the hammer die and one with the reverse image from the anvil die. I may have discovered the uniface struck obverse of this 1979D cent. Similar to the Mint creating an underweight planchet by tooling this coin, the Mint may have performed the foregoing unconventional minting procedure to obscure that it had created an experimental cent in case it were ever to be inadvertently released into circulation.
As a side note, this coin appears to have been improperly annealed as there is pitting that can be clearly seen on its reverse, rims and edge.
Finally, it is also possible this coin is the result of a post-mint alteration. I do not know, however, why anybody would create such a time-consuming alteration (or even have the means to do it outside a mint) and then place it into general circulation -- just for fun.
In my opinion, this is truly a great numismatic brain teaser. If any of you have any advice on this oddball 1973D cent, I would welcome your comments. Thanks for your assistance in advance.
Comment