1988 Mexico 20 Pesos

The 1988 20 Pesos coin was the first bimetallic piece issued for general circulation in Mexico, combining a brass ring and a bronze center to symbolize the nation's blend of old and new cultures.

That design choice, while practical for security, reflected a shift in minting techniques after years of simpler alloys. The obverse shows the Mexican coat of arms, while the reverse depicts a stylized eagle and serpent, drawing from ancient iconography. I’ve examined dozens like it; the edges are often sharp, a sign of careful striking.

Mintage figures? They’re murky, lost in old records. No one’s pinning down an exact number these days.

The coin's bimetallic structure made it less prone to wear in daily use, which is more than I can say for some flimsy modern currency.