100 Pesos Estado de México - Gold and Silver Proof Issue

Part of Mexico's long-running series celebrating the individual states of the federation, this issue honors Estado de México — the most populous state in the country and the one that entirely encircles Mexico City without containing it. The series, launched in 2003, committed the Casa de Moneda de México to producing a separate bimetallic proof for each of the 31 states plus the Federal District, an undertaking that generated substantial collector demand both domestically and abroad.

The gold-in-silver bimetallic proof format was a deliberate prestige decision, distinguishing the state series from the more common silver-only commemoratives the mint was producing concurrently.