Reasons Your Rare Coin Might Receive a ‘No Grade’ Designation

As a serious collector or investor you spend a lot of time, energy and money building your rare coin portfolio. It goes without saying that quality trumps quantity, and although we always advise our clients to purchase professionally graded coins, sometimes this isn’t possible, and a coin is purchased without a grade. It’s always a risky option, even more so if you’re an amateur collector or don’t have access to expert advice. The truth is coin grading is a costly process; however graded coins fetch much higher prices than ungraded coins.

So what happens when, down the line, you send your ungraded rare coin to be professionally graded, only to have it returned with a ‘no grade’ designation? It’s disappointing to say the least, especially if you spent a considerable amount on the coin. Your first question is likely to be ‘WHY’? So with that in mind, let’s look at the 9 main reasons your coin can’t or won’t be graded.


1. Unnatural colouration
2. Mechanical damage
3. Environmental damage
4. PVC contamination
5. Improper cleaning
6. Mechanical repairs
7. Counterfeits and mechanical alterations
8. Altered surfaces
9. Mint made flaws

Unnatural Colouration

If a coin has been artificially toned, artificially coloured, or shows traces of dip residue it is likely to be returned no grade.

Mechanical Damage

Any marks, initials or engravings purposefully stamped onto a coin (for example chop marks common on Asian trade coins), or damage to the coin’s rim or border will also result in no-grade.  Slight scratches to the surface of a coin might be accepted, but not severe scratches.

Environmental Damage

Coins that have been unearthed after a long time, or sea salvaged coins are likely to have severe environmental damage, most likely corrosion, but it can also be other natural substances that have adhered to the surface of the coin. The exceptions are platinum or gold coins, which are essentially immune to corrosion.

PVC Contamination

This is one of the most common reasons for a no grade. Many amateur collectors unwittingly store their coins in PVC ‘flips’, however over time the PVC breaks down, leaving a green film on the coin. It’s possible to remove this, but it depends on how long the coin has been in the flip for and the extent of the damage. Either way, if you’re considering having your coins cleaned, make sure it’s done by a professional; otherwise cleaning can cause irreparable damage which will result in a no grade.

Improper Cleaning

A coin that has been improperly cleaned (either with a cloth or mechanically or chemically) is likely to have a highly polished or scratchy unnatural look due to the harsh action which damages the surface and destroys natural lustre. Hairline scratches are a common result of attempting to clean a coin by wiping it with a dry cloth.

Mechanical Repairs

Commonly, these are coins that were used as jewellery, but are then removed and attempts have been made to mechanically repair them. For example by plugging holes, repairing the rim if it was encased in circular bezel, or by smoothing a coin’s surface to remove scratches or corrosion.

Counterfeits and Mechanical Alterations

A coin that has been manufactured by anyone other than the original manufacturers or institution that authorized it is a fake or counterfeit coin. There are two types of counterfeit coins. Those that are intended to pass as current circulating currency and those that are intended to deceive investors and collectors of rare coins. Coins that have been mechanically altered may have an altered date or an added or removed mintmark.

Altered Surfaces

If a coin has been treated so that its general appearance has changed, it is considered to have an ‘altered surface’. Commonly, this includes polishing surfaces and adding ‘fill in’ substances to hide defects. An altered coin can also be ‘whizzed’, ‘polished’ or ‘burnished’ (buffed by hand) to create a polished appearance and to hide imperfections.

Mint Made Flaws

Sometimes, during the coin manufacturing process, a flaw occurs. Generally, minor flaws such as rim clips or laminations (separation of the metal) will not be graded whereas major mint errors such as off-centres or incorrect planchets (blank discs ready to be struck into coins) are graded as ‘Mint Error’ coins. Planchet flaws are the most common defects that result in no grade.

Did you know

The 1898 Single “9” is the most important African coin. Sold by Rare Coin Investments.

Understanding "No Grade"

Don't get caught out!

A guide to the states of condition that can cause a coin to be rejected for NGC certification.

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