A coin’s edge is an important side that professional graders/authenticators rarely overlook. What are they looking for? Damage and alterations are the first things that come to my mind; yet other attributes such as the edge type and style are also important.
Edge designs were placed on coins to guard against the practice of clipping when small amounts of metal were shaved (cut) from the coin thus debasing its intrinsic value. There are many types of edge devices, some very ornate. A majority of U.S. coins are found either with a plain or reeded edge.
The vast variety of other edge styles occurs on foreign coins from the 18th century to modern times. A quick look at the Krause world coin catalog will reveal that in many cases the edge variety of an otherwise identical coin can increase its value many times. Collectors must be mindful of this and also make sure that their coin has the correct edge type since in many cases a counterfeiter will duplicate the obverse and reverse of a coin yet take no regard for its third side, the edge. Knowledgeable numismatists will also count the number of raised reeds on a coin’s edge to verify its authenticity.
Perhaps the first thing most of us notice about a coin’s edge is its condition. The larger a coin, the heavier it is so it will be more susceptible to edge damage. As with most attributes used to grade coins, any damage can be expressed on a sliding scale – it’s just a matter of degree.
Most heavy coins will come with a few tiny nicks and bruises that are of no consequence. Nevertheless, as the imperfections become either larger, more numerous, or detracting, they can have a significant effect on the grade, value and desirability of a coin. Until the damage becomes large, it’s purely a subjective call. When the edge damage includes the rim or pushes metal into the field, it can be considered a major detraction that no one will like.
Since edge and rim damage can be so detracting, many coins are seen that have been repaired. This includes mount removals, restored edge reeding (Figure 1) and rim files. The end result depends on the skill of the craftsman making the repair and how successful he can blend the repair with the original surface of the coin. Fortunately, repairs are rarely hidden from a skilled examiner using a stereo microscope with fluorescent lighting. Unfortunately, an excellent repair may easily be overlooked using other methods of examination.
One uncommon and devious alteration to watch for is an embossed mintmark. These were first seen many years ago on Buffalo nickels and then on Morgan dollars. In short, a coin’s edge is drilled and a bogus mintmark is produced by squeezing the thin layer of surface metal above the hole into a tiny die. The “ANA Counterfeit Detection” reprint from The Numismatist magazine has an excellent discussion of this method of alteration.
Another defect to watch for when viewing a coin’s edge is a cast seam. Many cast fakes will have a raised ridge on their edge where the two halves of a mold were joined. This seam is generally filed down on “better” fakes leaving horizontal scratches on the edge. A cast seam is more difficult to hide on reeded edge counterfeits so they are often found with the seam in plain view (Figure 2).
If you discover an edge seam that appears to be an incuse line or single horizontal joint (Figure 3), you may be dealing with an electrotype counterfeit. It is very difficult to join the two thin halves of an electrotype together perfectly. In most cases, some of the base metal interior of the fake will be visible in the seam.
If you encounter a coin with a suspicious edge, you may wish to have it checked at one of the major grading services.