The coin in our picture has picked up some unusual gold and green toning. This happens when coins are exposed to corrosive atmospheres. Most Mexican 5 pesos look as if they are made of silver, even though they are really made of copper-nickel.
On the obverse you can see the seal of the United Mexican States, used by the government of Mexico in any official documents and coins issued by the federal authorities. It is a modified version of the national coat of arms, with the addition of the full official name of the country Estados Unidos Mexicanos, in a semi-circular accommodation in the upper part of the seal. These are modern coin made by non-precious metal and carry low value.
The catalog value goes like this:
worn: less that $1 US dollar
average circulated: $1
well preserved: $2
fully uncirculated: $4