1978 D Roosevelt Copper Dime

Thie weight seems pretty normal for a circulated dime (2.268g standard weight). This looks to me like a typical long-buried coin that someone's found with a metal detector and attempted to clean before putting it back into circulation. On the obverse the original color is showing through on the highest parts of the portrait.

It's most likely a buried and recovered coin as NumisRob said.

Missing clad is almost always found only on one side of a bonding error coin. Due to the missing material of the planchet they are usually weak strikes. If both clad layers were missing the strike would be very weak across both the obverse and reverse of the coin. There are coins with both clad layers missing, but only a few have ever been certified as such.

Note on the coin the color on the tops of the tallest devices. When the coin is back into circulation, these higher areas will start of show the original color again, but a duller gray color:

Note the color is brown, not red like the copper layer on these found coins.



On a true missing clad, the color will always remain red and will not come back with circulation to gray again. These coins will be lower in weight and and have a weaker strike:



Same for dimes:




CoopHome: Why are some clad coins a different color? Enviormental issues alter coins color - how different than a clad missing error?

I will have to agree that this may just have been a buried or discarded/lost coin in the dirt.