Coin engraving is an art that can turn ordinary cuts of metal into valuable pieces of money. Today, coin engraving is considered a skill, and engraved coins are prized pieces not only for coin collectors, but for people who wish to commemorate special occasions as well. In the old days, coin engraving was done entirely by hand, with the occasional help of a magnifying glass. Today, coin engraving can be more precise and accurate, thanks to the help of coin engraver’s microscopes.
Not all coins are minted to be circulated and traded as money. In some countries, special occasions such as the crowning of a new king, the wedding of a celebrated politician, or the inauguration of a new leader are marked by the creation of hand-engraved coins. In both these cases, a coin engraver’s microscope is needed to not only create the engraving, but to inspect the coin molds as well.
Creating Coins for Circulation In the past, coins were created by the use of dies. A coin die is a carved piece of metal that is used to create an impression on the side of a coin; a die contains an incuse, or depressed image, of the impression that is meant to be placed onto the coin. Because the image is inverted and depressed, once the die is struck onto the coin, the resulting image will be in relief, and will contain readable words or numbers.
Dies today are created with the help of both people and machines. First, the engraving artist creates a model of the coin on a large block of plaster. Hot rubber is poured over this large version of the coin, coating the model’s surface to create a rubber mold. This rubber mold of the coin now shows the incuse, as it is meant to be seen on the die. The rubber mold serves as the model for an epoxy galvano version of the incuse, which, in turn, will be used by a reducing lathe as the basis for designing a smaller steel version of the incuse.
It takes the lathe a few days to reduce the coin’s future image onto steel, creating a steel master hub. After a tempering process to make the hub harder, master dies are made from the hub; working hubs are made from these dies; and working dies are made from these hubs. In the end, there are hundreds of working dies that can all work in concert to stamp images onto coins that will eventually go into circulation.
Each step of this process requires a good deal of security, in order to ensure that no coin-making secrets will leak out to counterfeiters; as well as a good deal of quality control, to ensure that no mistakes are made. In many of these steps, a good stereo microscope is needed for inspection.
A stereo microscope works like any ordinary microscope, except that it provides a three dimensional magnified view of a specimen. In this case, a stereo microscope, now used as a coin engraver’s microscope, is used to create a precise plaster model of the coin. If any mistakes are made in the plaster model, they can carry over into the working dies. A stereo microscope is also used to inspect the hubs and dies, in order to ensure that the minted coins are of the finest quality.
In some cases, even working hubs and dies can create imperfections in coins; some dies are not pressed well enough onto the metal, or the impressions are incorrect in terms of motto spellings and dates. The coins created from these mistakes become prized collector’s items.
Engraving Special Commemorative Coins Sometimes, special coins can be made by hand and used to celebrate special occasions. In this case, engraving artists can use tools similar to those used by engraving artists who specialize in adding names to metals such as ballpoint pens or fountain pens. This metallic engraver can carry out precise engraving movements, such as creating ridges or depressions, all with the help of a stereo microscope.
A coin engraver’s microscope, in this case, has to always be aligned and cleaned so that a line of personally designed coins will all be the same. Because custom designed coins are difficult to make, they can be expensive. They will often have exclusive designs, such as a family crest or motto, the date of the special event, even the signature of the engraver!
Coin engraver’s microscopes, due to the nature of their work, have to be well protected from flying metal debris, as well as the high pressure air that is used to clean out metal surfaces. For more information on such microscopes, visit your local coin collecting shop, or talk to engravers about their special art. Thanks to innovations in technology and metallurgy, coin engraving is easier, but nonetheless an interesting art to understand and observe.
