DurfDuck Posted January 27 Share Posted January 27 (edited) I would appreciate any information about what this oddity is and how it happens. Thanks! Edited January 27 by DurfDuck Link to comment Share on other sites More sharing options...
Popular Post Coinbuf Posted January 27 Popular Post Share Posted January 27 The coin has been subjected to high heat. That caused the clad layer to separate and expand like a balloon. As it cooled the clad layer bubble fell back and this is the result. EagleRJO, DurfDuck and Sandon 2 1 Link to comment Share on other sites More sharing options...
Sandon Posted January 27 Share Posted January 27 Welcome to the NGC chat board. I agree that the deformity of your 1994-D (?) Roosevelt dime was caused by exposure to high heat after the coin left the mint, possibly from an acetylene torch. Note how the surface of the coin has been blackened. Although "occluded gas bubbles" occasionally form when a planchet is struck, they are said to be restricted to solid-alloy issues and not to occur on clad coins like this one. See https://www.error-ref.com/?s=occluded+gas+bubble. The examples of coins with such bubbles shown in the link (1958-D and 1949 Lincoln cents) do not resemble this clad dime. Contrary to what you may have seen on some websites, it is extremely unusual to find any coin that exhibits a significant mint error in your pocket change. DurfDuck 1 Link to comment Share on other sites More sharing options...
Greenstang Posted January 27 Share Posted January 27 Welcome to the Chat Board As stated, an occulated gas bubble can only occur on a solid alloy coin, mostly on Lincoln Cents. What you have is caused by heat and have the nickname Campfire Coins. We see these quit often on the various coin forums so they are not unusual. DurfDuck 1 Link to comment Share on other sites More sharing options...
DurfDuck Posted January 27 Author Share Posted January 27 Thank y'all so much. Very helpful! Link to comment Share on other sites More sharing options...
