Milled Pillar Type
A new type of silver coin was created by Spain in 1732 that featured the twin globes and Pillars of Hercules, which were meant to symbolize the unification of the New and Old World under the Spanish crown. The opposite side displayed the name of the current monarch and his coat of arms. Many consider this the first universal coin, and it was minted until 1771.
Bust Type
A bust-style coin features the name and portrait of the current monarch on one side and the coat of arms, pillars and crown on the opposite side. These coins were minted between 1772 and 1821 and feature Carlos III, Carlos IV and Fernando VII. During early American colonial times, this was considered the most accepted and popular coin.
Spain, Provisional Government -- 2 Pesetas
This silver coin was issued during the provisional government of Spain, which existed between 1868 and 1871. The coin itself was issued in 1870, is 26 mm in diameter and weighs a little less than 10 grams. It was issued in Madrid and features a graceful queen and the word "Espana" on one side. The reverse features the traditional coat of arms, Pillars of Hercules and crown.
Alfonso XIII -- 5 Pesetas
This coin was issued in 1888 when King Alfonso XIII was only three years of age. His father (Alfonso XII) died young, making Alfonso XIII king from the young age of six months old. The coin features the profile of three-year-old Alfonso on one side and the traditional coat of arms, crown and Pillars of Hercules on the reverse side. It is 37 mm in diameter and weighs nearly 25 grams.