Spanish Dollar or Spanish Colonial Pillar Dollar of Mexico 1735, Silver 8 real coin of Philip V of Spain.

world coins Spanish dollar real silver coin
Spanish dollar coin
United States coins Spanish Colonial Pillar Dollar silver coin
 Spanish Colonial Pillar Dollar of Mexico 
Pillar Dollar or Spanish dollar - Spanish Colonial Silver 8 Reales Coin of 1735 MF, Mint Mark: Mo (Struck at the Mexico)
Spanish Colonial Pillar Dollar or Spanish Dollar silver coin served as the unofficial national currency of the American colonies and the new United States of America.

Obverse: Crowned Spanish coat-of-arms, assayers’ initials and value on either side.
Latin Legend: * PHILIP . V . D . G . HISPAN . ET IND . REX * / .MF* / *8*
Translation: "Philip V by the Grace of God, King of the Spains and the Indies"

Reverse: Crowned hemispheres, set on Gibralter, between crowned and banner-entwined pillars of Hercules.
Latin Legend: VTRAQUE VNUM * Mo * I735 * Mo *
Translation: "On both sides / Unity"

Reference: KM-103. R!
Weight: 26.78 gram of  Silver
Diameter: 41 mm

The Spanish dollar (also known as the piece of eight (peso de ocho), the real de a ocho or the eight-real coin) is a silver coin, of approximately 38 mm diameter, worth eight reales, that was minted in the Spanish Empire after a Spanish currency reform in 1497. Its purpose was to correspond to the German thaler. The coin could be physically divided into eight pieces, thus the name "pieces of eight".

The Spanish dollar was the coin upon which the original United States dollar was based, and it remained legal tender in the United States until the Coinage Act of 1857. Because it was widely used in Europe, the Americas, and the Far East, it became the first world currency by the late 18th century. Aside from the U.S. dollar, several other existing currencies, such as the Canadian dollar, the Japanese yen and the Chinese yuan, as well as several currencies in Latin America and the Philippine peso, were initially based on the Spanish dollar and other 8-reales coins. Diverse theories link the origin of the "$" symbol to the columns and stripes that appear on one side of the Spanish dollar.

The Spanish 8 reales was the world money standard from the time the Mexico Mint started striking coins in the late 1530's until the 1850's. The New World 8 reales and the subsidiary 4 reales, 2 reales, 1 reales and 1/2 real started out as crude "cob" coins (See: Spanish Treasure Coins) with irregular shapes, often with parts of the design missing. This made it difficult to ascertain that the coin weighed the proper amount (27.03 grams).

The Spanish Milled Dollar was a term English speakers gave to the Spanish 8 Reales that was minted on a coin press from 1732-1826. The term "milled" refers to the fact that the coin blanks ( planchets ) were made on a milling machine and were of consistent weight and size. The introduction of this technologically superior product kept Spanish coins as the basis for the world monetary system.

Starting in 1732 the Mexico Mint began minting coins with the flans held by a collar that impressed a security device on the edge. These coins are round and feature the Pillars of Hercules surrounding crowned, conjoined globes and ocean waves below, hence the other name for this coin, "Pillar Dollar". To the left of the date is the mint mark. The reverse shows a crowned shield with the assayers initials to the left and the denomination in reales to the right.

Many countries, European and Asian, counter marked Spanish Milled Dollars for use within their own countries. In the United States these coins were legal tender up until the Civil War period. Milled Dollars had a powerful effect on the U.S. coinage system. Our dollar was based on the Spanish Milled Dollar and some of the slang expressions referring to this money still survive today. As an example, the 8 Real was often cut into 8 "bits" to make change. Each bit was worth 12 1/2 cents (100 divided by 8). Though rapidly fading now, the expression 2 bits still refers to a quarter dollar.