1975-D Roosevelt Dime
Struck on 2.6g Copper Planchet
PCGS MS 62
This is a fascinating new discovery. U.S. Roosevelt Dime off-metals are very rare. There are only a few known on smaller copper or aluminum foreign planchets.
This Roosevelt Dime was struck on a heavier copper planchet weighing 2.6 grams creating a full-size dime off-metal. According to the extensive 69 page Mint Error News report on foreign coins struck at the U.S. Mints, this copper dime off-metal does not match any known foreign coin. It is a mystery why it was struck and is a dramatic mint error.
Another full-size dime off-metal is a 2018 Roosevelt Dime was struck on a full size steel planchet weighing 1.5 grams. It is as struck with blazing luster, has no surface marks or distractions, and was weakly struck due to the hardness of the steel planchet.
This 2018 Roosevelt Dime was struck on a full size steel planchet weighing 1.5 grams.
The Mint Error News website has a 69 page report of coins struck by the U.S. Mint for foreign countries. It is the most comprehensive report available anywhere.