This is likely Enviornmental damage. Also there were plenty of dimes struck in Philadelphia in 1968 which do not have mint marks. The proof from San Francisco is the rare one without the mint mark.
The core is copper. And the clad layers are 75% copper, but it's not a copper dime. It's just a dime. If it was a copper dime, (clad layer missing) the copper would be very bright.
And Missing Clad Layer errors usually occurs just on one side of any clad coin. I agree with Environmental Damage Worth 10 Cents Also.. You can't strike a Dime onto a copper planchet because it would not fit into the chamber that holds the Dime Planchet since it's bigger. Your Dime would be the same size, width and weight of a copper Cent.
I really do thank all of you for the knowledge you shared with me on your coins I must have a misunderstanding of what I read about the 68 dime where the clad comes off on one side or the other I did see that but even though there is none known to existence there is that possibility that it all would come off of the coin and I don't understand how egg dime like that one would be shining if it was copper because copper does oxidize
Missing clad layer occurs before the Blank Planchet is even punched from the long strip of metal used. The clad was not applied properly to one side. It is super rare to find a clad coin with both sides missing. It won't look like your Dime. Once again I say.. It is just Environmental damage. I have seen hundreds of dimes such as yours when I dig them up while metal detecting. Yours looks like a beach sand find because of the surface appearance. Kind of a smooth sandblasted look
Hey paddyman98. About your comment no common sense I like to say I am new to the coin collecting I inherited a lot of coins and that's why I asked about things I'm unsure of now if you're too bull-headed to be open-minded about all the clad being off of a dime and I guess I'll just have no common sense then open your eyes man think positive stay positive keep it simple
Happens after the blank is punched. An area of one of the clad layers isn't properly bonded to the copper core and after the blank is punched the "loose" clad layer falls away, sometimes before and sometimes after the coin is struck. If the clad layer was missing before the blanking the two layer strip would have still been rolled to the proper thickness and a missing clad layer coin would not be underweight. Also a coil of strip with a clad layer missing would surely be noticed. Of course what you meant might have been that the CAUSE of a missing clad layer happens before the blank is punched, which IS true.
It is No Common Cents.. Not sense. It's only a joke not meant for you in any way! Sorry you misunderstood. I'm only trying to help.
What good are the ears if the mind is blind... My apologies paddy man98 thank you for the information,
