Has anyone ever seen German coins like these? With the black background? They are not corroded or dirty. These were made to look like this. The rest of the coin is a shiny silver. I can not find, anywhere, this coin with the black.
It is zinc and that is the reason for it's black look. This is the zinc corroding, and definitely not how they were meant to look. The coin does have a nice looking circam to it.
This is what someone else told me but I disagree. I have about 20 of these coins and they look exactly the same. Sharp edges with the black and no discoloration. The black field is solid. You would think there would be varied color as it was corroding over the years.
Nope natural color for oxidizing zinc. But you can disagree. These were not made to look this way. By the way you are now outnumbered 2 to 1.
They just look too perfect compared to the way other coins look when this happens. So then what would the material be made of that didn’t oxidize? Would they make a coin with different metals for different features?
CircCamis when the coin has either toned over into the terminal black color, or has been corroded. Then pocketed and circulated, it wears off the high points on the design revealing the original metal composition. Here is a CircCam V Nickel. Below is a thread dedicated to the look you see on your coin. What is a "CircCam", you ask? Look and see! And post yours! | Coin Talk
From the hairlines present on the 5 of the coin you posted, I think someone may have run it across fine sandpaper to make the details of the design "stand out",. Which gives it a contrasting color, cameo effect. If the coins where stored in an environment that turned them black the complete surface of the coin would have oxidated evenly. JMO https://en.numista.com/catalogue/pieces1917.html
