Thanks. That does seem to be a possibility given the grime on the coin. However, I was puzzled looking at the reeded edge, as the nickel layer is quite thin, almost non existent.
I don't think it can be a spooned coin because the reeding is still there. Spooning would have wiped those out.
Did you weigh the dime? A coin missing one clad layer should be under weight. If it is missing both clad layers then it should be very under weight. Also the coins missing a clad layer are thinner so I think they typically have a softer strike. Try weighing your dime if you haven't and let us know.
Thanks for the tip on weight. For my 1989-D in question, I will have to wait to do that until I acquire a scale. Have plans for a scale in the near future so eventually I will be able to answer this.
that is what I was told when I showed a very dark one that I thought was missing layer...dug up from ground
It is most likely a dime that spent a while (many loads) inside the fins on the drum of a commercial dryer like in a laundromat. You can usually tell the difference between a spooned and dryer coin by the faces of the coin. A coin that someone tried spooning and then gave up before getting very far will only have the normal wear on the faces of the coin (and maybe a scratch or two depending on how careful the spooner was) and a dryer coin is usually mushy all over, like your dime.