2005 Penny - Lines And Zinc Rot?

, glad you can ask us!

You are quite right on the zinc rot diagnosis on the reverse, and those linear lines you see are roller lines from when the metal was being rolled into the proper thickness.

Also a good idea to show us the whole coin in one shot of both sides to give us a good idea of what the coin is like. Really good pictures by the way!

Zinc rot is like the equivalent of a zombie, dead but not as its still spendable. In 1982 when the rising cost of copper made the cent more expensive to produce than its face value, a new composition of copper-plated zinc was adopted for the cent. These cents had a core composed of 99.2% zinc and 0.8% copper, with a plating of pure copper. It is a very unstable combination. Often around the mintmark, small breaks of the plating occur as the coin is struck. That spot is a prime target area for corrosion to begin under the copper plating. https://www.error-ref.com/zinc-dete...ncoln-cents/ Other reasons like on your coin such as damage can also allow the zinc core to be exposed. Unfortunately these dont have a premium, are common, and usually will get worse over time if the zinc continues to be exposed to the atmosphere.

Wow... thank you so much for explaining that. I better start spending them. I will check out the link you provided me.

to the CCF!

Roller lines are on the planchets. Die scratches will be on the dies. You coin looks like the dies are polished, thus the reduction of size on the devices. Also the polishing was to remove DDD areas on the devices towards the closest rims. You can see a hint of this still on the left sides of the devices on Liberty. But a coin in this condition, should have been tossed when found. All premium for these coins are gone when the zinc is exposed.