The percentage of Silver in the Mexican peso has an interesting history spanning centuries. As early as the 1500s, the Spanish started mining Silver and made coins that came to be called the Spanish real (rreh–ahl). As the real became more popular, it quickly became one of the most widely accepted international currencies – which opened the door for potential counterfeits on a large scale. Security measures were taken in attempts to reduce counterfeits, such as more detailed designs and lettering on the edges of the coins. During this time, the weight of the Silver and Gold coins was carefully controlled, which led to their well-known names, peso de oro and peso de plata – literally meaning the weight of Gold and the weight of Silver, respectively. The common peso coins were 27.468 grams of 93.5% pure Silver, which equaled eight Spanish reales.
Over the years, as political and economic times changed, the Mexican peso experienced a series of devaluations. Through these devaluations, the percentage of Silver in the Mexican peso was reduced to only 10% by 1957 – which were some of the last Silver one-peso coins produced by the mint before they switched to bimetallic coins. Relatively small numbers of these historic 1957-1967 Silver Mexican 1-peso coins, with their 10% Silver content, remain today because millions were melted down for their Silver content in the years past.
