Reveal Your Coins’ True Beauty
The professional conservationists at NGC use a variety of proprietary techniques to remove harmful contaminants, stabilize and protect a coin’s surfaces and, in many cases, improve a coin’s eye appeal. Since, 2001, NGC has conserved more than 1 million coins, tokens and medals.
A professional approach to numismatic conservation
From within a state-of-the-art secure facility, NGC’s conservationists use a variety of proprietary techniques to remove harmful surface contaminants, stabilize and protect a coin’s surfaces, and improve eye appeal. The American Numismatic Association (ANA), the only coin collecting organization chartered by US Congress, and the Professional Numismatists Guild (PNG) have named NGC their conservation service of choice. Read more >
Entrusted with the world’s most extraordinary coins
NGC has conserved and preserved many of the world’s most important numismatic rarities and collections, including pieces from the Smithsonian Institution. In addition to these rare and valuable vintage coins, NGC has handled coins recovered from four major shipwrecks along with countless modern coins.
What is numismatic conservation?
Collectible coins are susceptible to damage and changes of appearance as a result of improper storage and packaging, adverse environmental effects, mishandling, and natural changes over time. Surface contaminants such as PVC and other residues, soils, tarnish, spots and encrustation can diminish eye appeal and even permanently damage coins.
NGC pioneered a professional approach to numismatic conservation and can safely remove these harmful surface contaminants and often dramatically improve a coin’s eye appeal. Unlike improper cleaning, which will permanently impair a coin’s surfaces, professional conservation from NGC reveals a coin’s originality.
NGC will never perform repairs such as filling holes or smoothing scratches, or do any type of mechanical alteration. The techniques used by NGC are non-invasive and widely accepted by industry experts.
Join now to submit your coins to NGC!
Join todayWhat NGC Conservation can do
Prolonged exposure to an unstable environment can cause coins of all types to develop haze, spots, encrustation, verdigris, corrosion and tarnish. NGC specializes in the removal of these harmful surface contaminants and the stabilization of a coin’s surfaces. Read more >
Conservation for vintage and modern coins alike
All coin types can be affected by surface contaminants and negative environmental reactions. In many cases, coins have been stored or sold in soft plastic flips or mint packaging that contains polyvinyl chloride (PVC), a chemical now known to slowly leach onto the surfaces of a coin. If not safely removed, PVC and other residues will eventually result in permanent damage.
Some of these issues will make a coin ineligible for grading by NGC, if not first addressed by professional conservation. After conservation by NGC, coins will be sent directly for certification and, depending on the surface condition, will be numerically graded or NGC Details graded.
Important Note: Many coins are artificially toned or have had substances applied in attempt to hide other problems such as scratches or improper cleaning. These issues may become apparent after NGC removes the artificial toning or applied substances, but they are in no way caused by NGC’s conservation techniques. None of NGC’s techniques will cause scratches or an “Improperly Cleaned” notation at NGC.
PVC, glue and dip residues
Residue caused by PVC holders, glue or dip chemicals can often be safely removed by NGC Conservation. If left untreated, these residues can permanently damage a coin’s surfaces. Many modern Chinese coins have been sold in packaging that contains PVC.
Copper spots on gold coins
Unattractive reddish spots are often seen on gold coins. Gold is frequently alloyed with copper, and high concentrations of copper at the coin’s surface can result in reddish spots. NGC can carefully remove these spots to improve the coin’s eye appeal.
Haze
Many coins, particularly delicate proof coins, can develop haze on their surfaces over a period of time. This haze can be caused by improper storage or environmental conditions, or it can occur naturally over time as contaminants react to a coin’s surfaces.
Soils and encrustation
Many types of contaminants caused by storage and the environment can be removed by NGC, with the result being a dramatic improvement in the coin’s eye appeal.
Unattractive tarnish / toning
Virtually all metal types develop toning naturally over time. In some cases, toning can be quite attractive and desirable. In others, however, it can severely diminish eye appeal. In many cases, NGC can safely remove or minimize unattractive toning.
Artificial toning
A coin’s natural toning is sometimes artificially accelerated by chemicals or excessive heat. NGC can often remove this artificial toning to restore a coin’s originality — though removal may reveal previously hidden problems such as scratches or improper cleaning.
Applied substances
NGC can remove many substances applied to the surfaces of coins to change their appearance, such as putty or lacquer. As with artificial toning, removal may reveal other surface problems, and the coin may still receive an NGC Details grade after conservation.
What NGC Conservation cannot do
Though NGC Conservation benefits many coins, there are certain problems that cannot be remedied, such as corrosion, wear, scratches, and white “milk” spots. NGC does not make repairs and, likewise, cannot undo mechanical alternations. Read more >
Important Note: Hairline scratches and other surface issues caused by improper cleaning are often disguised with artificial toning or applied substances. Artificial toning and applied substances can be removed by NGC Conservation, which will then reveal the improper cleaning underneath. None of NGC’s techniques will cause an “Improperly Cleaned” notation at NGC.
White “milk” spots on modern silver coins
This form of corrosion is caused by the mint’s manufacturing process and can develop anytime, from right after striking to many years later. NGC cannot remove these unpredictable spots, but rest assured that none of NGC’s techniques cause them, either.
White “milk” spots can negatively impact a coin’s grade at NGC, but NGC cannot be liable for spots that occur after encapsulation. The NGC Guarantee specifically excludes coins “exhibiting environmental deterioration subsequent to certification. These issues include but are not limited to spotting, hazing, PVC and corrosion.”
Learn more about white spots >
Improper cleaning
Many coins have been permanently altered by amateur cleaning, leaving fine scratches and other surface issues that cannot be fixed by NGC Conservation. Sometimes these alterations are only revealed upon removal of artificial toning or applied substances.
Mechanical repairs
NGC cannot undo or hide mechanical repairs such as tooling, plugged holes, rim repairs and re-engraved details. NGC also cannot remove solder from coins. In most cases these coins are eligible for NGC Details grading.
Damage, graffiti, wheel marks and countermarks
Damaged coins, including those that are bent, holed or have wheel marks, graffiti or countermarks, cannot be repaired by NGC. In addition, NGC cannot repair coins that are mounted or have been removed from mounts or jewelry.
Damage, graffiti, wheel marks and countermarks
Damaged coins, including those that are bent, holed or have wheel marks, graffiti or countermarks, cannot be repaired by NGC. In addition, NGC cannot repair coins that are mounted or have been removed from mounts or jewelry.
Damage, graffiti, wheel marks and countermarks
Damaged coins, including those that are bent, holed or have wheel marks, graffiti or countermarks, cannot be repaired by NGC. In addition, NGC cannot repair coins that are mounted or have been removed from mounts or jewelry.
Damage, graffiti, wheel marks and countermarks
Damaged coins, including those that are bent, holed or have wheel marks, graffiti or countermarks, cannot be repaired by NGC. In addition, NGC cannot repair coins that are mounted or have been removed from mounts or jewelry.
Scratches, abrasions and wear
The natural effects of circulation — scratches, abrasions and wear — cannot be undone. NGC does not re-engrave details, plug holes, or perform any type of repairs. Similarly, NGC does not repair or disguise planchet flaws.
Severe corrosion
Corrosion affects virtually all metals. A chemical reaction, corrosion causes the molecular makeup of a coin’s surfaces to change. Though NGC can stabilize a coin’s surfaces and prevent further damage, it cannot reverse corrosion that has already occurred.
Add “red” to copper coins
A copper coin's color can change naturally over time from red (noted as “RD” on the NGC certification label) to red brown (“RB”) to brown (“BN”). This is an irreversible process and NGC Conservation cannot change the BN, RB or RD designations assigned to copper coins.
The NGC Conservation Process
-
NGC conservationists evaluate your coin
NGC first evaluates a coin to determine if it will benefit from conservation. If it will not benefit from conservation, the coin goes directly to grading.
-
NGC conserves your coin
If NGC determines that a coin will benefit from conservation, it performs the necessary conservation techniques. After conservation is complete, the coin proceeds to grading.
-
NGC Grades your coin
After conservation, coins are seamlessly transferred to authentication, grading and encapsulation. Once the coin has been graded and encapsulated, it is shipped back to the submitter.
Frequently asked questions
What is NGC Conservation?
What coins can benefit from NGC conservation?
How much does NGC Conservation cost?
Does NGC offer any type of guarantee for conservation?
What happens when NGC Conservation evaluates a coin?
Does submitting for conservation mean that I will get a higher grade at NGC?
Can NGC Conservation add "red" to copper coins?
How do I contact NGC Conservation?
What if I submit a coin for both conservation and an NGC ReGrade, but NGC declines to conserve the coin?
Read the latest news and announcements! NGC News >
Add Coin
Join NGC for free to add coins, track your collection and participate in the NGC Registry. Learn more >