what would cause a well worn 1920 penny to look like dirty silver in color .. over the entire coin (even edges) ?? weighs 2.9g so does that mean its just well worn or is it some reaction that the copper had?
You are likely right on the weight. A worn cent, doing its job 100+ years later. Kentucky is right about the coins...especially older ones. Different shades...different colors.
The coin does not look silver to me. It looks shiny brown with a dark surface starting to corrode. On the obverse, above the "W" and "T" I can see fresh copper color where the oxidized surface is scraped off.
It all has to do with what the coin was exposed to in its lifetime. There are always environmental factors both natural and manmade, dirt, grime, heat, smoke, chemical exposure that will affect a coins patina and darken the color based on the base composition/metallurgy of the coin. I have had several mint state Buffalo nickels from a roll that had turned a deep gloss black and when I sent them into a TPG service, they came back graded as details, Environmental Damage.
Copper is the most reactive of the three classic coinage metals. It can take on many shades. The early large cent expert, Dr. William Sheldon, once called it “autumn leaves.” He put together a color set of copper coins, which the last I knew was on the market for a very high price. The other two classic coinage metals are silver and gold. They are classics because they are among the least reactive metals to the elements.
I'm not seeing it in the photos, but if you are while in-hand, it is most likely as others have said, although, coming in contact with certain other materials, a coin could take on a variety of colors, but usually NAV, and not any type of error. Have you ever watched the videos of turning pennies into silver and even gold color? Just do a search on YouTube for them.
Copper takes years to react with normal atmosphere to produce Copper Oxide which starts brown with a change to black if Carbonated water is present. ( Now you know why your "cup holder change" looks like it does. IMO, Jim
Once again I am not saying that any coin that I put on here is worth any money or some terrific find or I just won the lottery of treasure hunting. I'm asking questions so I better understand this industry and that is it and only it but thank you for your advice I will take a look at that
Sorry if you thought I was referring to you believing it was something special or valuable. That wasn't my intention. I appreciate posts that will further the knowledge of the recipients.
I have a few cents that have that same look. I believe the wear and oil from our fingers gives it that shiny silvery look. It’s still brown like copper should be but the light makes it shine and the wear is reflecting a silver like color.