Following Christopher Columbus’s discovery of the New World, the territories of what today is considered Mexico were in the early 1500s absorbed into the Spanish Empire. Spanish settlers soon discovered that Mexico was rich in minerals, especially in silver. With commercial activities growing in Mexico, there was an ever-increasing demand for coinage that would expedite this trade. Considering the abundant supply of silver ore, the logical decision was taken in 1535 to establish a mint in Mexico City. The Mexican mint, which also minted the 50 pesos gold coin, began to strike the Spanish 8 real silver dollar coin in the late 1530s.
Thanks to royal Spanish manuscripts, a great deal is known about how the Mexican mint operated in its founding years. The mint offered refining and assaying services, and the mintage of coins. Whenever merchants were in need of coinage, they turned to the Mexican mint that provided them with coins in exchange for a fee. The transaction between these two parties happened in the following way: either the merchant could bring his own silver, which was then melted, assayed and struck into coins, or he would buy silver bars at the mint’s foundry and have them re-shaped into coins. For example, if the merchant bought the silver at the mint’s foundry, he then had to pay a fee of two reales (2 x 3.195 grams of silver) for every 214 grams of silver he wanted turned into coinage. Thus, the mint’s fee turned out to be approximately 3% of the total weight that was due to be turned into coins.
Almost 35% of this fee went to the supervisors who ran the operation of the mint, 32% went to the mint’s treasury, the coiners received 11%, the assayer and the die-sinkers each received 7%, and the last amount was split between the weigh-master, the secretary, the overheads and the guards.
Once the contract between the mint and merchant was agreed upon, the merchant’s silver was taken into a designated area of the mint where the metal was assayed and rolled into strips. The strips were cut into round planchets that were then weighed to ensure that the weight was correct. Thereafter the planchets went through an annealing process. This means that the coins were heated and cooled at a specific temperature in order to restore the ductility that had been lost when the metal was rolled and cut. Finally, they were placed between two dies (metallic pieces that contained the image to be transferred onto the coin) and were struck with a hammer to produce Spanish silver real coins.
The Mexican mint is today still in operation, making it the oldest mint in the Americas. Besides being responsible for minting Mexico’s circulating coinage, it also produces what many consider to be one of the most beautiful investment-grade bullion coin series, the gold and silver Libertad coins.