The overwhelming majority of all US Proofs, of all denominations, have been minted in Philadelphia until the last 15 years. Beyond the fact that only a very poor proof looks as bad as the very finest MS Prooflike (a hint as to the reason for that term) specimens, the way to tell them apart is by using the work of collectors who came before you. For each series, someone, somewhere, has painstakingly recorded all the minor die variations which distinguish mint strikes from proofs. That knowledge is hard to come by for free, but always available somewhere.
And, to throw a wrench into the works, some business strike coins were minted using proof dies after they became to worn to produce acceptable proofs. Therefore, they have the same distinguishing marks as proofs.
There is an entire world of knowledge to acquire for each and every mintage, in order to become competent at discerning proofs from business strikes. This is not a hobby for the easily-discouraged researcher.
And, to throw a wrench into the works, some business strike coins were minted using proof dies after they became to worn to produce acceptable proofs. Therefore, they have the same distinguishing marks as proofs.
There is an entire world of knowledge to acquire for each and every mintage, in order to become competent at discerning proofs from business strikes. This is not a hobby for the easily-discouraged researcher.




















