What could have happened to the dark cent, wrong planchet, fire damage, etc.? Dark cent 19.5 - 20 mm, 2.49/2.50 g, obverse: convex, reverse: concave Regular cent 19 mm, 2.48/2.49 g
Please explain, I'm sure you mean something coin related. I believe heat/fire could have caused the entire look.
...also explains the coating melting away, minor traces left near rim. The nice penny shows that the cheap thin layer wears off with just circulation, you can see through the plating.
Yeah, maybe. But I've seen a lot of heated coins and never saw one go concave because of it. Expand a bit ? Yes, but only temporarily. As soon as they cool they shrink back to normal. Spooning however will cause a coin to become concave, every time. If you don't know spooning is when you continually tap on the edge of a coin with a spoon. This gentle but continuous tapping causes the edge of the coin to expand and get larger and larger over time. It also bends the edge in a single direction eventually making the coin very concave. Eventually to the point where the edge is so wide, bent over itself and putting inner portions of the coin on the edge and the center so concave that the center can be drilled out and the coin worn as a ring.
