Altered Coin (ALT)

An altered coin is a genuine United States Mint product that somebody modified after it left the Mint, so that it appears to be a rarer date, a rarer mint, or a more valuable variety than it is. The metal, the dies and the strike are all authentic; one detail has been added, removed or reworked by hand. That makes an alteration a different thing from a counterfeit, which is fabricated rather than modified, and a different thing again from post-mint damage, which is incidental rather than deceptive. The three are often confused, and the distinction is most of the diagnosis: a counterfeit usually fails a measurement, while an altered coin passes every measurement and fails under magnification in one small place.

Key dates that have a far more plentiful sibling — the 1916-D Mercury dime, the 1909-S VDB cent, the 1914-D cent, the 1937-D three-legged Buffalo nickel — are the dates most often faked this way, because the donor coin is easy to find and already genuine. NumisDex records alterations so they can be identified, not collected: an altered coin has no catalog standing and no grade, and the major grading services return it in a details holder or not at all.

Altering a coin with intent to defraud is a federal offense under 18 U.S.C. § 331, which covers the fraudulent alteration, mutilation and falsification of United States coins.

How Does It Happen?

Added Mint Marks

The most common alteration. A mint mark is cut, soldered or pressed onto a coin that was struck without one, turning a Philadelphia issue into a branch-mint one. The 1916 Mercury dime, the 1909 VDB cent and the 1893 Morgan dollar are classic donors, because in each case the Philadelphia coin was struck in much larger numbers than the branch-mint coin it is made to imitate.

The work is done in one of three ways: a mint mark cut from a genuine donor coin and attached; a mint mark built up from solder or metal filler and shaped; or an impression pressed into the field with a punch. All three disturb the surrounding field, and none of them reproduces the exact shape, size and position of the Mint's own punch for that year.

Altered Dates

A digit is reshaped, removed or added so the coin reads as a rarer year. The best-known case is the 1944-D cent re-cut into a 1914-D: the first 4 is ground down and reshaped into a 1. Date alteration leaves tool marks, an incorrect numeral shape, and spacing that does not match the Mint's date punch for the claimed year.

Removed Design Elements

Metal is filed or polished away to imitate a genuine variety the Mint created by accident. This is the category that most rewards knowing the genuine error. The famous 1937-D three-legged Buffalo nickel and the Buffalo nickel "two feathers" varieties are not alterations — they are die abrasion varieties, produced when a Mint pressman over-polished a die and took design with it. Because the genuine varieties exist and are collected, fakers imitate them by removing the same detail from an ordinary coin by hand.

The difference is decisive and visible. The Mint removed the detail from the die, so the loss appears on every coin struck from that die, surrounded by the die's own polish lines and with the adjacent design undisturbed. A faker removes the detail from the coin, so the loss is unique to that specimen, surrounded by tool marks, and the metal the tool displaced shows up somewhere nearby.

Joined and Machined Novelties

Two-headed and two-tailed coins are made by machining two genuine coins to roughly half thickness — one losing its reverse, the other its obverse — and joining the halves by solder, press fit or adhesive. They are manufactured and sold as novelties and magician's coins rather than as rarities, but they reach the hobby as "is this a mint error?" constantly.

Surface Alterations

Whizzing (wire-brushing the surface to imitate mint luster), tooling (re-engraving worn detail), artificial toning, plating and re-coloring all change a genuine coin's appearance without changing its identity. These do not turn one date into another; they inflate apparent grade or eye appeal. A copper-plated 1943 steel cent belongs here — the coin is a genuine 1943 steel cent wearing a copper coat, not a 1943 bronze cent.

How to Identify an Altered Coin

The governing principle: a Mint variety repeats, an alteration does not. Anything that happened to a die appears on every coin that die struck, which is why genuine varieties have published die markers — a die crack in a fixed place, a specific polish pattern, a known mint mark position. An alteration happened to one coin and has no markers, because there is nothing to repeat. If a coin shows the headline feature but none of the variety's other diagnostics, the headline feature was added.

• Weigh and measure first, but do not expect them to fail. Unlike many counterfeits, an altered coin was struck by the Mint on a correct planchet and will sit inside tolerance. A normal weight rules a counterfeit out; it rules nothing out here.
• Examine at 10x to 20x, at the feature itself. Alteration is local. The rest of the coin is genuine and will look it, which is exactly why a general impression is no use.
• Look for a disturbed field around a mint mark. A genuine mint mark was punched into the die, so the coin's field flows smoothly up to it. An added mint mark sits on a surface that has been cut, filled or abraded, and the boundary shows as a seam, a halo of disturbed metal, or a break in luster.
• Compare the punch, not just the letter. Mint mark style, size and position changed over the years and are documented date by date. An S of the wrong style for the year, or a D sitting away from where the Mint put it, settles the question without any metallurgy.
• Watch for differential toning. An altered area tones at a different rate from the original surface. Under a lamp, a mint mark that is brighter, duller or a different color from the field around it is reason enough to stop.
• Check the edge on any two-faced coin. A machined-and-joined novelty shows a seam, a thickness slightly under standard, or a step where the two halves meet. Rotate it under a light and the seam catches.
• Reach for a magnet on anything claimed to be off-metal. A copper-plated 1943 cent is magnetic; a genuine 1943 bronze cent is not. See Wrong Planchet for the genuine transitional errors and their weights.

Genuine Variety or Alteration?

Notable Examples

1916-D Mercury Dime

The 1916-D has a mintage of 264,000, against more than 22 million 1916 Philadelphia dimes that carry no mint mark, which makes the added D a frequently encountered alteration. Genuine 1916-D mint marks have a documented shape and position on the reverse, to the left of the fasces; added marks are commonly the wrong style, set at the wrong angle, or ringed by disturbed metal.

1909-S VDB Lincoln Cent

The usual alteration is an S added to a genuine 1909 VDB Philadelphia cent, which has no mint mark. NGC points to the shape of the S as the test: San Francisco used a single S punch on its Lincoln cents from 1909 to 1916, and a genuine mark usually shows a small raised dot inside the upper curve of the S, though the dot can be faint, so its absence alone does not condemn a coin.

1914-D Lincoln Cent

Created from a 1944-D by reshaping the first 4 into a 1. The quickest giveaway is the designer's initials: from 1918 on, VDB appears on the truncation of Lincoln's shoulder, so a "1914-D" with VDB there began life as a later coin. The reshaped digit also leaves a wider gap between the 9 and the following 4 than a genuine 1914-D shows.

1937-D Three-Legged Buffalo Nickel

The genuine coin is a die abrasion variety — the reverse die was polished so heavily, reportedly to remove clash marks, that the bison's right foreleg between hoof and thigh disappeared, while the hoof remained. The imitation is a normal 1937-D with the leg removed from the coin. NGC lists the genuine coin's other markers: heavy die erosion at the back of the Indian's neck, and a line of small raised die lumps under the bison's belly (often called the "stream"), which can be worn away on low-grade coins. Altered pieces lack those markers, and the field where the leg was shows polishing that the rest of the field does not.

1943 "Copper" Cents

Nearly every 1943 cent that looks copper is a genuine 1943 zinc-coated steel cent that has been copper-plated. It is magnetic, and it weighs about 2.7 grams rather than the 3.11 grams of a bronze cent. The genuine 1943 bronze cent is an off-metal transitional error, covered under Wrong Planchet.

Two-Headed and Two-Tailed Coins

Machined from two genuine coins and joined. Sold openly as novelties, they often arrive in the hobby as suspected mint errors. The edge seam is the tell.

Collecting Tips

• An altered coin has no grade. PCGS and NGC return alterations in details holders or decline them altogether. They have no catalog standing, which is the practical reason to identify one before money changes hands rather than after.
• For key dates, buy certified or buy expert eyes. The dates listed above are the ones worth paying a grading fee on. A raw 1916-D, 1909-S VDB or 1914-D offered cheaply is the shape of the problem, not of the opportunity.
• Learn the genuine variety's full diagnostic list. The surest defense is not knowing what fakes look like but knowing what the real one must show. Every genuine die variety has more than one marker, and an alteration can only supply the famous one.
• Photograph the feature, not the coin. When asking for help, a sharp image of the mint mark, date or missing element at high magnification answers the question. A full-coin photograph almost never does.
• Keep a magnet and a scale within reach. They will not catch an added mint mark, but they settle the off-metal claims in seconds, and those are the claims that arrive most often.