1964-P Lincoln Memorial Cent - How Is This Caused?

Thanks Mike. I assume you've examined these up close. Now I'm intrigued by how this could be done, especially when looking at the "D" in UNITED. There is a mirror image inside the loop of it. The "shadow" runs around the entire coin with no signs of any other damage to the devices (at least that I can tell).

I don't know exactly how the effect is produced. Far more severe examples exist and they're totally incompatible with anything a coinage press could produce. So I feel safe in extrapolating from them to more modest examples like the coin shown here. Unlike Die Deterioration, the letters are often thinner than normal and the coin's weight is also often reduced. Notice as well that the design rim shows the same pattern of "ripples". You won't see this in a genuine case of Die Deterioration. How about a photo of the edge, while we're at it? A genuine error will show no effect on the edge, while these "rippled" coins often do.

I'll weigh it and get a pic of the rim when I get home tonight after work.

In answer to Steve199's question, yes, all of the odd effects are post-mint.

OK. Weight is 3.09 g. Here are pics of the rim.

I also noticed (this time), that there is an extra "flap" of metal on most of the devices, best shown on the left side of the "U" and "N" below, which may help in the diagnosis or support the oven theory.

Wow! So, I guess that's where my coin was headed if they decided they wanted it well-done instead of medium-rare?

I haven't tested it yet, but one of my theories is that some keeps running a blow torch across the surface over and over in one direction.

I see all the serious rippling on your two coins, but not the doubling that appears on mine.