General terminology:

Added Mintmark indicates that the coin’s mintmark has been applied fraudulently to enhance its value.

Altered Date describes a coin that has had its date changed by any means in an attempt to increase its value.

Altered Surface is a general term used to describe a coin whose surfaces are clearly not natural but whose exact treatment is uncertain. Among the deceptive processes that fall into this category is the application of pastes to either hide contact marks or to simulate Cameo frosting or Prooflike brilliance.

Artificial Color refers to bronze, copper and copper-nickel coins that have been chemically dipped or cleaned. Under natural conditions, most copper coins will darken over time, but examples that retain their original “red” color are highly valued. That’s why “Red Brown” (RB) or “Brown” (BN) copper coins are sometimes treated to remove this toning. The resulting color usually has an unnatural and artificial look.

Artificial Toning refers to the process whereby patina is imparted to a coin in an accelerated reaction process using chemicals and / or heat. Artificial toning may be removable with proper conservation by NCS but, since it often hides improper cleaning or other surface issues, the coin may yet require Details Grading.

Bent coins are simply that — they show a non-mint-made curvature when viewed on end.

Bronze Disease is a term describing a form of corrosion unique to copper or bronze coins that typically affects ancient coins.

Brushed describes a coin that has been wiped with an abrasive brush. The affected areas may be narrowed down to OBV BRUSHED or REV BRUSHED.

Burnished is the term used when the cleaning is more aggressive and gives the coin a very brilliant but unnatural sheen. Sometimes this action is performed with some abrasive media such as ball bearings, or it may result from treatment within a rock tumbler.

Chopmarked coins have had Asian characters punched into them as assurances of their value by the merchants who handled them many years ago. This was a common practice with silver coins, particularly trade dollars, circulating in Southeast Asia.

Chopmark Repair reveals that a chopmark has been fully or partially effaced through tooling or filling.

Clipped Planchet refers to a portion missing from the edge of a coin’s planchet. A large missing area is gradeable as a Mint Error, while very small clips will result in Details Grading only.

Corrosion is a problem for most metals, though gold and platinum are nearly immune to its effects. A natural chemical reaction, it causes the surfaces of a coin to form new molecular compounds. Light corrosion results in the often pleasing condition of toning. When corrosion is severe or unattractive, it results in coins certifiable only under Details Grading. NGC’s graders may narrow down the problem area by using the terms OBV CORROSION, REV CORROSION and EDGE CORROSION.

Countermarked coins have had a figure or character punched into them by some non-official agent, such as a merchant or jeweler. Lacking any official sanction, these punchings are considered just damage.

Damaged is a catchall term used when the coin displays any form of destructive contact that may not be defined more precisely. This may be narrowed down a bit by specifying OBV DAMAGE, REV DAMAGE, RIM DAMAGE or EDGE DAMAGE.

Dip Residue describes a coloration that results from a coin being chemically cleaned (dipped) to remove toning and not properly rinsed off afterward. This makes the coin have a cloudy or brown unnatural look.

Environmental Damage is the result of a hostile storage environment, where the exact cause of the surface damage is indeterminable.

Glue Residue is self-explanatory, and may be treatable with proper conservation. NGC’s graders may narrow this down to read OBV GLUE or REV GLUE. Such coins should be submitted to NCS for removal of this material.

Graffiti describes a coin into which initials or some other writing has been scratched or carved. This may be narrowed down to read OBV GRAFFITI or REV GRAFFITI.

Illegible Date is self-explanatory. If the exact date cannot be determined for any reason, then the coin is not eligible for grading.

Illegible Mintmark may be due to wear, damage or extreme die erosion and will not be graded.

Impaired is used to describe Proof coins that have received light circulation or mishandling, but whose Proof surfaces remain detectable, even if marred or worn.

Improperly Cleaned is a generic term to describe unskilled cleaning when the exact nature of the action is uncertain.

Ineligible Type describes a class of coin, medal or token that NGC does not certify, regardless of its condition.

Insufficient Detail to ID applies mostly to Ancient coins, but this restriction is in effect for all coins, medals and tokens that are of indeterminate identity.

Lacquered coins have had a coat of clear lacquer applied in an attempt to prevent tarnishing, a common practice in past decades. The terms OBV LACQUER and REV LACQUER provide greater specificity. Proper conservation by NCS may be able to remove this contaminant.

Mounted refers to some sort of jewelry attachment still present with the coin.

Mount Removed indicates that the coin was formerly mounted to a ring or bezel and that this attachment has left evidence of its one-time presence. Most modern bezels are designed to secure a coin without doing any harm, but some older ones resulted in a crimping effect.

Mutilated coins display an extreme form of damage, whether intentional or accidental.

Not Genuine means that the piece is either a souvenir replica or a counterfeit. Circulating counterfeits are contemporary with the coins they imitate and are intended to pass as money at their face value. Numismatic counterfeits are intended to deceive collectors and typically are made years after the originals.

Planchet Flaw describes a void or lamination (separation) in a coin’s planchet as made. OBV PLANCHET FLAW and REV PLANCHET FLAW provide a guide to the problem’s location.

Plugged coins are ones that were previously holed, typically for suspension as jewelry, and have had their holes filled in to conceal the damage. As the affected area usually includes design features, these will show evidence of re-engraving.

Polished is similar to Burnished, though it’s typically applied when the abrasive action is less severe.

PVC (polyvinyl chloride) film on a coin’s surfaces will preclude encapsulation by NGC, as this continues to be an active contaminant and may cause further damage. Such coins should be sent to NCS for removal of PVC through proper conservation.

PVC Damage indicates that a coin has been irreparably harmed by environmental reaction to the chemical plasticizer in plastic coin holders. PVC is a widely used thermoplastic that has many applications. In the numismatic field it is found in the manufacture of “flips,” the transparent, dual-pocket envelopes used by dealers, collectors and grading services for displaying and handling coins. This plastic is safe enough for short-term use, but long-term storage brings with it a serious hazard. To make PVC flexible, it is impregnated with a chemical plasticizer that, over time, separates from the PVC base and may form a green film on the surface of a coin. If left untreated, the plasticizer combines with moisture in the air to create hydrochloric acid that etches the coin’s surfaces. When caught in time, the PVC contaminant may be removable through NCS conservation.

Questionable Authenticity indicates that there is reason to doubt the genuineness of a submitted coin, though it may be impossible to ascertain definitively.

Re-engraved describes a coin that has had worn or damaged details replaced through the use of engraving or chasing. This may be narrowed down by stating OBV RE-ENGRAVED or REV RE-ENGRAVED. A related repair is ETCHED STARS, these peripheral features being among the first to wear down on older coins.

Removed from Jewelry is more or less self-explanatory but is used when the more specific damage descriptors are not enough to fully describe the effect.

Removed Mintmark, like its counterpart Added Mintmark, is a fraudulent attempt to misrepresent the value of the coin.

Residue describes some surface contaminant that cannot be identified more specifically by NGC’s graders. OBV RESIDUE and REV RESIDUE provide a guide to the contaminant’s location when it appears on just one side. With proper conservation, such residue may be removable before it results in environmental damage.

Rim Filing is done to coins to remove irregular metal or to even out their rims. It may be used to obscure normal circulation damage or signs of jewelry use. OBV RIM FILED and REV RIM FILED are used to identify the specific area affected.

Rim Repair describes work performed to obscure either naturally occurring or intentionally inflicted damage. A common cause of such damage was the attachment of coins to pins or rings, as well as encasement of a coin within a bezel or “lucky coin” frame.

Scratches of a very minor nature may permit a coin to be certified, but use of this term in Details Grading indicates that the damage is more severe.

Smoothing is akin to Tooled (see below), but it is used when the exact means of achieving the described effect is unknown.

Soldered describes a coin that has been used as an item of jewelry and still displays evidence of this traditional bonding agent. Solder may or may not be removable with NCS conservation.

Spot Removals describes the unskilled, mechanical removal of “flyspecks,” small black spots of intense toning or corrosion. It also refers to similar removal of reddish “copper spots” often seen on gold coins.

Stained coins display discoloration but not corrosion. More often than not such staining is irremovable. When isolated to one side, it is described as OBV STAINED or REV STAINED.

Surface Hairlines are faint, abrasive lines that disturb a coin’s appearance, even though some original surface may remain underneath. They typically result from gentle rubbing with a cloth, and their severity may be described more fully through addition of the terms LIGHT, MODERATE or EXCESSIVE.

Tooled refers to either the smoothing of a coin’s fields to remove scratches, corrosion and other forms of damage or to the restoration of lost details through use of a graver or knife. When a single side of the coin is affected, the terms OBV TOOLED and REV TOOLED are used.

Wheel Marks occur when a coin-counting machine has left a shallow indentation on the coin, resulting in a highly polished spot. This may be narrowed down to specify OBV WHEELMARK or REV WHEELMARK.

Whizzed coins have been cleaned with a fast, rotary wire brush in order to simulate the effect of mint luster on a circulated coin. These are easily spotted by experts, as their lettering and other design details typically are distorted a bit by this action.

Wiped describes a coin that displays surface hairlines in one or more isolated areas. This is usually the result of accidental mishandling rather than intentional cleaning, but it still requires Details Grading. NGC’s graders may specify OBV WIPED or REV WIPED to more accurately describe the condition.