Understanding Coin Grading And How Color And Luster Factor In

If you have some antique coins in your possession that are placed in inexpensive mylar or cardboard holders, then it may be in your best interest to have the coins graded and placed in slabs. Slabs are archival holders made from firm, hard, and transparent acrylic. The holders are used to retain the condition of the coin inside so it does not become marred or scratched in any way. The grade of the coin will be printed directly on the slab. The grade directly corresponds to the value of the coin, and there are several factors that determine grade. While some factors, like the general condition of the coin are obvious, others like color and luster may seem a bit more confusing. Keep reading to learn about these factors and how they are considered when grading a coin.


Color is a factor that determines grade in a few different ways. Color can add beauty to a coin, and good aesthetic value is something that is required for a coin to be graded favorably. Aesthetic value is somewhat subjective, but grading companies do consider the types of things that a collector looks for when assessing beauty. 

Color can also be a way to determine the types of preservation methods used to retain a coin. Preservation is another factor that is highly important when grading a coin. For example, a large penny coin that has a bright red hue can signify an uncirculated coin that has been preserved with care. Specifically, careful storage techniques were used to keep the coin away from moisture and heat. 

A highly circulated large cent would have a more brown appearance with bits of red across the coin. Typically, more brown will appear on the exterior, while the internal portion of the coin will be more red. This shows that oxidation has formed and the coin was likely circulated. If the coin was not stored correctly, then the oxidation will be deeper, and this will negatively affect the grade of the coin. 

The color of the coin may also be changed by cleaning methods. It is often unwise to clean a coin unless it it covered in a layer of dirt and debris. If cleaning is necessary, then this should be completed by a professional. However, even professional cleaning can alter the value of a coin slightly because the coin will react to cleaners like acetone.

If the coin was previously cleaned by someone, then this will be apparent in the color as well. In particular, the chlorine in tap water can disrupt the natural coloring. Also, some people tend to use nail polish remover instead of pure acetone to clean coins, and the other chemicals in the product can cause staining. Even the presence of hand oils can cause changes in the color of the coin. While past staining and discoloration cannot be reversed, new types of damage can be avoided with the placement of the slab on the coin. 

Another thing you should know about color is that certain colors and hues may appear when a coin is altered in some way. Alterations are typically performed to make a coin look more appealing, and they can reduce the value of a coin to almost nothing in some cases.


Luster is another factor looked at when grading, and it is closely related to condition and preservation. Simply put, the luster is the sheen or the reflection on the surface of the coin. A high-luster coin does make it appealing and worth more. However, the luster also provides information on how the coin was minted. For example, if a coin is created with a more precise minting process, like when a proof or a special mint coin is formed, then the luster will be greater than that of a coin minted for circulation.

If a coin was created as a proof, was preserved properly, and was never circulated, then you will see something called a mint luster. In other words, the coin will have the same shine as it did when it was first minted. These coins are worth the most.

Most coins will have a somewhat dull appearance due to circulation, and the degree of the dullness will be considered, and the coin will be graded accordingly.

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