Mintmarks off, mintmarks on; who keeps it straight?

What would a late summer morning be without familiar numismatic topics?

Yesterday, it was Lincoln cents.

Today, a typed letter came my way via snail mail with a question about mintmarks on Roosevelt dimes.

The collector who wrote found a 2000-dated dime with a “P” mintmark on it and wondered if it was an error.

Naturally, I had to write back that all Roosevelt dimes struck at Philadelphia have had a “P” mintmark on them since 1980.

That’s 28 years ago since the “P” was added to Philadelphia dimes.

I also get mail from people wondering whether their pre-1980 dimes without a mintmark on them are an error.

Both lines of inquiry seem to be inspired by stories of the proof set errors where various coins since 1968 are missing a mintmark.

Many writers who contact me by email don’t know what proofs are.

They don’t know that they are sold only by the Mint directly to collectors in sets.

That is one point I cannot seem to get through the language barrier to a correspondent in Russia who keeps sending me photos of ordinary 1990 Lincoln cents from Philadelphia that have no mintmark on them.

He keeps telling me he has the 1990 “No S” proof cent that’s worth a lot of money.

I keep telling him they are ordinary Philadelphia strikes.

He asks how I can tell.

The circle goes round and round.

When I was a kid, it was just the war nickels of 1942-1945 that ever hosted a “P” mintmark.

Then, during the Jimmy Carter presidency, the Mint decided to raise Philadelphia’s level of recognition by putting a “P” on coins.

Chet Krause, among other collectors, objected to the end of the tradition of the mother mint having no mintmark.

As a sop, the Mint continued that tradition but with the cent only.

That then changed for one year in 2017 when the “P” was put on the cent to celebrate the 225th anniversary of the Mint.

The first coin since war nickels to carry the “P” mintmark was the 1979 Susan B. Anthony dollar.

Then, in 1980, the “P” mintmark was put on Philadelphia nickels, dimes, quarters, and half dollars as well.

I have been answering letters about mintmarks or their absence ever since.

Buzz blogger Dave Harper won the Numismatic Literary Guild Award for Best Blog for the third time in 2017 . He is editor of the weekly newspaper "Numismatic News."