Grading Systems and History of Japanese Antique Coins
The evaluation of Japanese antique coins has traditionally been based on a unique grading system. This system classifies coins into five grades: "Mishiyō (未使用)" (Uncirculated), "Gokubihin (極美品)" (Extremely Fine), "Bihin (美品)" (Fine), "Namihin (並品)" (Fair), and "Reppin (劣品)" (Poor). This system was cultivated within the culture of coin collecting that has continued since the Edo period. "Mishiyō" refers to a nearly perfect condition in which the coin retains the luster it had at the time of minting and shows absolutely no wear from circulation. The presence of mint luster on the surface is an important criterion for this judgment. The next grade, "Gokubihin," refers to coins that are in an overall very beautiful condition, though with only very slight wear or marks. "Bihin" refers to a condition in which wear from circulation is evident, but the characters and designs can still be clearly read. It is common for coins in this grade to show signs of use in everyday transactions. At "Namihin," there is considerable wear, and it becomes increasingly difficult to read fine details. "Reppin" refers to coins with major losses, corrosion, or significant deformation, and virtually no collectible value can be expected. This traditional grading standard is still used today by many collectors and dealers within Japan. However, in terms of objectivity and international applicability, more detailed numerical grading has been attracting attention in recent years. This basic grading system is indispensable for understanding the factors that determine the value of antique coins.
The 70-Point Numerical Grading System by PCGS and NGC
In the international antique coin market, 70-point numerical grading by third-party authentication services such as PCGS (Professional Coin Grading Service) and NGC (Numismatic Guaranty Corporation) is the mainstream standard. This is a system that evaluates the condition of coins in greater detail and more objectively; coins are encapsulated in transparent special cases called "slabs," with both grade and authenticity guaranteed. The 70-point grading scale is divided into the following categories: MS (Mint State: Uncirculated) 60–70, AU (About Uncirculated) 50–58, EF (Extremely Fine) 40–45, VF (Very Fine) 20–35, F (Fine) 12–15, VG (Very Good) 8–10, G (Good) 4–6, and PO (Poor) 1–3. MS70 is the highest grade, considered "absolutely perfect," referring to a condition in which no flaws can be found with the naked eye. This numerical grading system provides peace of mind to both buyers and sellers, particularly in high-value antique coin transactions and international auctions. The cost of authentication is approximately 5,000 to 15,000 yen per coin as a general guideline, and the cost-effectiveness increases for higher-value coins. The specific authentication process can be confirmed in the Practical Guide to Coin Grading.
The Value Indicated by Sub-grades and Special Designations
In grading by PCGS and NGC, sub-grades and special designations indicating the characteristics of a coin may be added in addition to the main numerical grade. These represent important information for collectors and have a significant impact on market prices. For example, "+" (plus) is assigned to coins that are in particularly good condition within the same grade, suggesting quality close to the next grade up. Additionally, proof coins may receive designations such as "CAM (Cameo)" or "DCAM (Deep Cameo)." These indicate the degree of contrast between the frosted design elements and the mirror-finish background of the coin, with DCAM considered a rarer item possessing deeper contrast. Furthermore, designations such as "FS (Full Strike)" or "FB (Full Bands)" may be used for coins with certain designs. These indicate that the fine details of the design were fully struck at the time of manufacture, and coins receive high marks especially when areas that are difficult to strike remain clearly defined. Coins awarded these special designations tend to command significantly higher market values even at the same numerical grade. For example, "Proof-like" and "Deep Cameo" Meiji gold coins are extremely popular among collectors and are traded at higher prices than ordinary MS-grade pieces. Please also refer to Types and Values of Meiji Gold Coins.
The Exponential Relationship Between Grade and Price
It is not uncommon for the price of an antique coin to change dramatically with just a single-grade increase. The price increase is exponential particularly for high-grade coins. As a concrete example, let us look at Tenpō Tsūhō (天保通宝), a representative Japanese holed coin. While a Tenpō Tsūhō graded AU53 (About Uncirculated) may trade at around 20,000 to 30,000 yen, at MS62 (Uncirculated) it can reach 100,000 to 150,000 yen, and at MS65 or above it can exceed 300,000 yen. This price difference stems from the extremely small number of surviving high-grade examples. Among antique coins, which are prone to wear through circulation, coins that have survived while retaining their condition at the time of minting are extremely rare. In the realm known as "Gem Mint State" at MS65 and above in particular, even a slight difference produces price discrepancies of several times or even tens of times. When considering antique coins for investment purposes, insisting on a perfect coin such as MS70 limits purchasing opportunities and requires an enormous budget. For this reason, the MS62–65 range, which is said to offer a good balance between liquidity and potential price appreciation, is generally considered to hold the greatest investment appeal. By checking price trends in the market chart, you can grasp specific price movement tendencies.
Points to Note Regarding Cleaned Coins and 'Details' Grades
One of the most important points to be aware of in coin grading is the treatment of "cleaned coins." When PCGS or NGC authenticates a coin and discovers artificial cleaning or alteration, it is judged as a "Details grade" rather than a standard numerical grade. This indicates that the surface of the coin has been altered from its original state. For example, notations such as "MS Details – Cleaned" or "AU Details – Scratched" are recorded on the slab. Details-grade coins generally see their market price fall by 30% to 50% or more compared to a properly graded coin in the same condition. This is because cleaning is considered to have diminished the coin's historical value and originality. When purchasing, it is essential to carefully check the slab notation and confirm that the coin is not a Details grade. Furthermore, cleaning a coin yourself after purchase should be absolutely avoided. There is a risk that a properly graded coin could be downgraded to a Details grade, resulting in a significant loss of asset value. Please also refer to the Complete Guide to Identifying Fakes and Altered Coins to develop the ability to detect unnatural alterations.
Japan's Domestic Authentication Organizations and International Evaluation
Domestically, there are coins accompanied by certificates issued by the Japan Numismatic Dealers Association (JNDA), which are trusted among Japanese antique coin collectors and dealers. The JNDA is an organization whose members include the major long-established coin dealers in Japan with a long history, and its certificates provide a certain standard of quality and authenticity assurance. There are also cases where long-established coin dealers and authenticators specializing in specific genres, such as Ginza Coin and dealers specializing in error coins, issue their own individual certificates. While these certificates receive a certain level of recognition in the domestic specialist market, they do not have the international applicability of PCGS or NGC. In transactions with overseas buyers and at large-scale international auctions, evaluation based solely on JNDA or individual certificates is often limited. If you are considering selling in overseas markets or transacting with international collectors in the future, it is advisable to consider applying for authentication by PCGS or NGC from the outset, as this makes it easier to ensure liquidity. It is important to understand the characteristics of both the domestic and international markets and to select the appropriate authentication organization.
Advantages and Disadvantages of Slabbed Coins
Coins encapsulated in slabs by PCGS or NGC offer many advantages and a few disadvantages. The main advantages are four points: ① authenticity guarantee, ② objective guarantee of grade, ③ condition preservation through a sealed protective case, and ④ high international marketability. Especially when purchasing high-value coins exceeding 100,000 yen, choosing slabbed coins can reduce the risk of counterfeits to nearly zero, allowing transactions to proceed with peace of mind. In future sales as well, having a guaranteed grade can be expected to facilitate smooth transactions. On the other hand, disadvantages include the additional cost of authentication, the fact that the grade guarantee becomes void once the case is opened, and the constraints on storage and transport due to the increased weight and size including the case. Furthermore, in Japan, some traditional collectors tend not to prefer slabbed coins because they cannot directly handle and appreciate the coin. For this reason, evaluations of slabbed coins may be divided in domestic face-to-face transactions and at some specialist dealers. When considering proper storage methods for antique coins, storage methods also differ depending on whether the coin is slabbed or not.
Points to Note for Self-Assessment and How to Develop a Grading Eye
Coin grading is highly specialized, and it is difficult for beginners to accurately grade coins based on their own judgment. In particular, the appearance of a coin changes greatly depending on the angle of light and how photographs are taken, making it easy to overestimate. The first step is to develop the habit of handling the actual coin and observing it from various angles under multiple light sources. As a practical method for developing a grading eye, make full use of online images in the Pop Report (Population Report) published on the PCGS and NGC websites. By comparing your own coins against images of the same coin type—in Fine, Extremely Fine, Uncirculated, and other grades—listed in the Pop Report, your sense of grading will improve dramatically. It is also effective to receive direct advice from trusted coin dealers and experienced collectors. It is indispensable for developing the "discerning eye" for grading to regularly attend auctions and exhibitions and accumulate experience actually seeing and handling a wide variety of coins. Understanding the types and classification systems of antique coins will also serve as an aid in deepening your grading eye.
The Correlation Between Grading and Market Trends
Grading is not merely an indicator of a coin's condition; it is closely correlated with the movements of the antique coin market itself. High-grade coins tend to attract market attention easily, and as competition intensifies among collectors and investors, the price volatility tends to increase. In particular, in genres that combine both historical and artistic value—such as gold and silver coins from the Edo period and early Meiji-era modern gold coins—the impact of grading on market prices is enormous. For example, a gold coin such as the Man'en Koban (万延小判) minted in the 1860s, when authenticated as uncirculated, commands a very high premium due to its rarity. This is because the supply of high-grade examples is limited while demand from collectors worldwide remains constant. As the market matures, the importance of grading will increase further, and authenticated coins will become the standard in international transactions in particular. The price trends of graded coins are also one important indicator for reading market cycles. By understanding how to read antique coin market cycles, more informed investment decisions become possible.
The Relationship Between Grading and Long-Term Preservation
While grading evaluates the current condition of a coin, a once-determined grade can easily decline depending on subsequent storage conditions. And there is the harsh reality that a grade, once it has fallen, can never be recovered. For this reason, proper preservation is extremely important for maintaining the value of high-grade coins. High-grade coins that are not encapsulated in a slab are particularly sensitive to environmental deterioration during storage. Humidity, extreme temperature fluctuations, direct sunlight, and chemical damage from holders containing PVC (polyvinyl chloride) can degrade the surface of a coin, causing corrosion and discoloration, and represent causes of significant grade decline. Fingerprint adhesion also requires attention, as it can become a cause of corrosion over time. Storage in dedicated PVC-free holders and in moisture-proof cabinets with controlled temperature and humidity is essential. Regularly checking the condition of coins and consulting a specialist promptly if any abnormality is found leads to the maintenance of precious asset value. Knowledge of grading, when combined with the correct Coin Storage and Maintenance Guide, truly demonstrates its full value.