From the listing I would say by the thickness (2.2 mm vs 1.6 mm) but I'm not sure how they can be the same weight and have a thickness that different with one being .900 silver and the other .950.
As best I can tell, the first one was not struck in proof, only the second.
If you do not know how to tell the difference between UNC and Proof, you can go to a coin store at look at examples of each. Generally speaking, the fields (flat area) of a proof have a mirror finish.
Stato cambiato a Risolto(Desdinova, 10 Dic 2025, 23:22)