@leni, most often when we see a groove around the rim like this, we ascribe it to the coin having been encased or in a bezel, as mentioned by @dear. I don't see how it could have left the mint looking like this.
"If you climb a good tree, you get a push."
-----Ghanaian proverb
"The danger we all now face is distinguishing between what is authentic and what is performed."
-----King Adz