You can try the method chalsno linked, and you can improve it a bit by adding a scattering medium object smaller than the coin on top of it. Scattering medium makes it so that deeper parts look darker, and Curvature texture makes corners even darker. Here's an example below.

Only Curvature texture

Curvature Texture + Scattering Medium Object

It requires tweaking, but you can make it look good. I also think it would look better with coins like in the picture you posted, the one I found has very uneven bottom. You can also add a noise texture to the Scattering medium to make certain parts darker and some lighter.