Hi
It all starts with Provenance,
Check your coin's Catalogue weight, Diameter
Even if it is slightly off size or weight, you might have a forgery
Check the lettering on the coin, misspellings, and differences in the coat of arms are all warning signs
Here is an excellent example of a fake coin.
https://www.ebay.com/itm/236242237768?itmmeta=01K3P4HDTT14ZAA2J3E0F77W2D&hash=item3701227948:g:YKsAAeSwq3xojd7d
Remember, the Price offered for a 1oz silver coin is ridiculous; it is not a Bargain, but a trap, a scam.
Always be alert!
Caveat Emptor - Buyer Beware !