Last summer I bought a Mexican 5 peso coin with the face of an Aztec king on one side, and an eagle on the other. I don't have a weighing scales, but it feels a similar weight to my Morgan dollars and Victorian crowns. The milling around the edge looks even, but I'm suspicious by the lack of wear or pitting. I scratched it with a knife to see if it was a forgery, and the metal underneath is a silvery color, but shinier than the outside. From the description, is this coin genuine, or a forgery?
The best way to tell, would be to get a scale and weigh it. Every coin collector should have one. You can also do a magnet test. But weighing it, should be a good start, to autenticate a coin.
You bought this and they are actually quite common so probably real. Also, just scratching the edge of a coin is never a good idea. Scales, rulers and magnets will always be better and this site for identification. http://www.ngccoin.com/poplookup/World-Coin-Price-Guide.aspx
