Black paint on coins

Dear, can someone explain to me what black color on coins is and what it is for. The pictures show copper coins in the original color or coated in black.

Have a nice day.

I didn't even have the courage to write but my grandson brought me a handful of coins right now and they seem to have the same rare patina . That they would be old rare coins? Definitely the effects of time and environment.
Unless someone wants to create such an idea , it is necessary to start from the intention producer. ( Sometimes the intention can be determined for profit)-and sometimes for play and joy, and there is a big difference in responsibility and morality.

Hi Ivan

• Interesting, thanks!
  

Some old coins were, many years ago, given a coat of clear varnish,
which over time has discoloured to be sometimes black.
This is a 1683 token I own which has very old discoloured varnish on it ...


Also, I know there was (about 120 years ago) the UK farthing coin which had to be chemically
darkened (using sodium thiosulphate) by the mint to stop the new shiny coins being
mistaken for gold sovereign coins.

Quote: "ZacUK"​ Some old coins were, many years ago, given a coat of clear varnish,
​which over time has discoloured to be sometimes black.
​ This is a 1683 token I own which has very old discoloured varnish on it ...
​
​
​ Also, I know there was (about 120 years ago) the UK farthing coin which had to be chemically
​darkened (using sodium thiosulphate) by the mint to stop the new shiny coins being
​mistaken for gold sovereign coins.

​Thank You!

It is quite attractive coin ,the highlights on dark field , eye catching

Yes, it looks very nice with accentuated details. That’s why I think someone deliberately added that color. At first I thought they were copies, and then I saw that such coins sell for more than $ 150.

you can get them authenticated by NGC or other similar. I think with coins this nice you can benefit.