The Sonora issue belongs to México's long-running "Estados de la República Mexicana" series, which ran from 2004 to 2007 and dedicated one 100-peso bimetallic coin to each of the country's 31 states plus the Federal District. Sonora's selection of imagery drew on the state's distinct cultural and geographic identity along the U.S. border — a region whose economy had been radically reshaped by the 1994 NAFTA agreement in the decade preceding this coin's issue.
The .925 silver centre is a meaningful specification: it matches sterling standard, making these among the higher-purity bimetallics in Mexican circulation coinage of the period.
The Sonora issue belongs to México's long-running "Estados de la República Mexicana" series, which ran from 2004 to 2007 and dedicated one 100-peso bimetallic coin to each of the country's 31 states plus the Federal District. Sonora's selection of imagery drew on the state's distinct cultural and geographic identity along the U.S. border — a region whose economy had been radically reshaped by the 1994 NAFTA agreement in the decade preceding this coin's issue.
The .925 silver centre is a meaningful specification: it matches sterling standard, making these among the higher-purity bimetallics in Mexican circulation coinage of the period.