Mint mark
For example, in 1649, the directors of the Spanish colonial American Mint at Potosi, in what is today Bolivia, were condemned to death for seriously debasing the coinage.
In some cases the symbols found in the field of ancient Greek coins indicated mints, not magistrates.
Mints in territories conquered by Alexander the Great struck coins with the types he used in Macedon but marked with a local symbol.
[2] A reform of Diocletian made mint marks a regular feature of ancient Roman coinage.
[6] In the fifteenth century letters or symbols placed at the end of the legend indicating the mint were used in addition to Secret Points.
[7] In 1540, Francis I discontinued Secret Points in favor of a system of letters; A for Paris, B for Rouen, …, Z for Lyon; in the field.
[8] He also made it the rule for mint-masters to place their personal marks on coins, as they had done with increasing frequency since the coinage of Louis XI.
[11] When William III retired hammered coinage, branch mints which helped strike machine made coins to replace it put their initials below his bust.
These issues show the initials of Sydney, Melbourne, Victoria, and Perth Australia as well as Canada, South Africa, and India.
After its revolution, Mexico continued to use its colonial Mo monogram mint mark shown on either side of the date in the Spanish Milled Dollar.
A turnaround began after 1893, when A. G. Heaton's "A Treatise on Coinage of the United States Branch Mints" was published.
Heaton cited example after example of mint-marked coins that were much scarcer than Philadelphia products and that should bring high premiums.
United States mint marks were originally used to distinguish coins not made in Philadelphia.
The West Point "W" mint mark was first used on the $10 gold coins commemorating the 1984 Olympic games in Los Angeles.
Most Philadelphia Mint coins from earlier than 1980 were unmarked with the notable exceptions being wartime nickels (1942–1945) and Susan B. Anthony dollars (1979–1999).
When Spain adopted decimal coinage in 1848, it used stars with different numbers of points as mint marks.
