What is Keichō Chōgin: The Starting Point of the Edo Silver Coin System
Keichō Chōgin (慶長丁銀) is the first official silver coin of the Edo shogunate, first minted in the sixth year of the Keichō era (1601) when Tokugawa Ieyasu achieved the unification of Japan. As the origin of ten varieties of Chōgin that followed, including Genroku, Hōei, and Tenpō, it boasts the highest standards in terms of fineness, design, and heft. Its shape is the product of the "Fukiya method," where craftsmen poured molten silver into sand molds and formed them into a loquat shape with both hands. The slightly varying contours of each piece continue to captivate today's collectors. The standard weight is roughly between 130 to 160 grams, but larger pieces exceeding 150 grams and smaller ones around 100 grams also exist, showing the diversity unique to weighed currency. Keichō Chōgin not only functioned as a cornerstone of the unified currency system of the Edo shogunate but also stands as evidence of the advanced silver refining technology of the time. For an overview of Edo silver coins, please see Introduction to Edo Silver Coins (Chōgin & Mameitagin).
Silver Fineness 80%: Its Meaning and Verification Method
The most significant feature of Keichō Chōgin is its high fineness of about 80% silver (800 out of 800 ≈ 800‰). This is the highest figure among the ten varieties of Chōgin from the Edo period, highlighting its high value when contrasted with the history of declining fineness in later recoins. The remaining approximately 20% mostly consists of copper, which is an alloy design to harden the silver and enhance its durability. When viewed in cross-section, Keichō Chōgin reveals a uniform silver-white metal layer, visually demonstrating its high fineness. In contrast, with increased copper content, Genroku Chōgin (about 64%) and Tenpō Chōgin (about 26%) often show a yellowish tint, allowing a rough estimation of the era based on color alone. Using XRF (X-ray fluorescence analysis), the fineness can be accurately measured non-destructively. When utilizing a professional appraisal service, requesting this analytical data markedly improves purchasing decisions. For general methods of authenticity judgment, also refer to Guide to Detecting Forgeries & Altered Items.
Types and Placement of Kokuin: Marks Proving Authenticity
Kokuin (極印) stamped on Keichō Chōgin is crucial evidence proving its authenticity and era. The main kokuin are classified into three types. First, the "Jōze" (常是) mark. It is an oval mark indicating the approval of Gotō Shōzaburō, the highest official of the Ginza (Silver Mint), and is often struck relatively large and clear on Keichō Chōgin. Second, the "Ginza" mark. It is a rectangular stamp inscribed with the character "銀" within which indicates the minting authority and may appear multiple times. Third, character marks indicating the era and fineness such as "長", "慶", and "保". The combination of these marks allows the estimation of the minting period. The more distinct the kokuin remains, the higher the evaluation. Conversely, partial damage or unclear marks are reasons for value reduction. Additionally, posthumously added fake kokuin exist; thus, experts need to collectively assess embossing depth, script style, and edge sharpness. Accurate appraisal requires an understanding of Grading Standards for Old Coins.
Existing Numbers and Rarity in the Market: Estimating Issue Volume
The exact issuance number of Keichō Chōgin remains unrecorded and is subject to various theories among researchers. However, many were collected and melted during later recoining, making existing Keichō Chōgin particularly scarce among all Chōgin. It is estimated that about 10 to 20 Keichō Chōgin appear annually in major old coin auctions in Japan, a notably lower figure compared to several dozen units of Tenpō Chōgin or Ansei Chōgin appearing in the same period. This scarcity is one of the key factors driving up market prices. The approach to collecting coins with low issuance is increasingly demanding from overseas collectors (particularly in Europe, America, and Southeast Asia), and during periods of yen depreciation, international bids become more active, resulting in winning prices exceeding domestic market prices.
Current Market Price: From Fair to Pristine Condition
The market price of Keichō Chōgin varies widely depending on the condition of preservation and the state of the kokuin. The following are guidelines based on major auction data from the 2020s. Fair condition (worn or dirty surface, unclear kokuin): 300,000 to 700,000 yen. Fine condition (generally clear with distinct kokuin): 800,000 to 1,800,000 yen. Very fine condition (retaining surface luster, complete kokuin): 2,000,000 to 3,500,000 yen. Extremely fine condition (near uncirculated with all kokuin clear): above 3,500,000 yen, sometimes exceeding 5,000,000 yen. Notably, when "large Keichō Chōgin" items exceeding 150g appear on the market, the competition among collectors tends to be intense due to the larger bullion weight. There have been cases where a well-preserved 160g class sold for over 4,000,000 yen. For the optimal exit strategy in selling, refer to Introduction to Antique Coin Auctions and Usage. Considering Keichō Chōgin has low liquidity, it is important to regard it as a long-term investment with a holding period of 3 to 5 years before selling.
Combination with Mameitagin: Added Value of Set Pieces
When Keichō Chōgin is stored together with "Keichō Mameitagin (慶長豆板銀)" minted during the same period, it receives significantly higher evaluation than a single piece. Mameitagin are small silver ingots used for fractional settlements and small trade transactions, serving as historical evidence of how Chōgin and Mameitagin were used in commerce at the time. When sets from the same era remain with original containers (such as wooden boxes or straw bundles), additional antique value is recognized. Items with accompanying certificates or documents indicating they were used in merchant transactions during the Keichō era may also be recognized for their academic value and become candidates for donation to museums. For more details on Mameitagin, see Explanation of Mameitagin (Mameitagin). For an overview of all Chōgin, please refer to The World of Chōgin.
Practical Detection of Authenticity: Common Forgery Patterns of Keichō Chōgin
Due to its high market value, Keichō Chōgin has been subject to forgery and alteration for a long time. Here, we organize the main forgery patterns and methods of identification. 【Later Cast Items】 "Replica Chōgin" manufactured during the Meiji and Taishō periods may be aged and circulated as genuine items. The identification method is by the quality of the casting marks on the surface and the aging of the silver color. Genuine Keichō Chōgin exhibits a unique sulfurization pattern that marks 400 years of time. 【Fineness Tampering Items】 Items that are only silver-plated on the surface, with copper, lead, tin, or other alloys inside. Detectable by XRF analysis and density measurement (compared to the pure silver density of 10.49). 【Replaced Kokuin】 Pieces that have Keichō kokuin stamped on the silver base of Ansei Chōgin. Be cautious if the embossing depth of the kokuin and the texture of the silver base do not match. To detect these forgeries, it is highly recommended to obtain certificates from certified members of the Japan Numismatic Dealers Association. It is extremely dangerous for beginners to make judgments on their own.
Proper Storage Methods: Long-term Maintenance of High Fineness Silver
Keichō Chōgin, with its high fineness of 80% silver, undergoes sulfurization (blackening) relatively quickly when exposed to sulfur and humidity in the air. Yet, properly stored pieces have demonstrated the ability to maintain excellent condition for over 400 years, as evidenced by existing Keichō Chōgin. The ideal storage environment is stable with relative humidity below 40% and temperature of 15 to 20°C. For individual storage, use "acid-free" mylar flips or coin capsules, and store them along with silica gel desiccants in airtight metal cans. Avoid using PVC vinyl flips as they can cause discoloration due to a chemical reaction with silver. Natural toning (darkening) over the years can be valued as evidence of history, but artificial polishing and cleaning significantly lower market value. Especially for high-value items like Keichō Chōgin, it is a principle to avoid any cleaning actions and not to maintain them without consulting experts. Refer to Proper Storage Methods for Old Coins for storage basics.
Sources and Cautions When Purchasing
Selecting a highly reliable source is the most important factor when purchasing Keichō Chōgin. Recommended purchase routes are listed in order of priority. Firstly, large specialized auctions (such as those hosted by the Tokyo Antique Society, Kokuenkai Auction, etc.). They allow for in-person verification before bidding, with pre-auction appraisals conducted. Secondly, stores that are full members of the Japan Numismatic Dealers Association. Members have undergone strict examinations, significantly reducing the risk of acquiring counterfeits. Thirdly, major international auctions (e.g., Heritage, Stacks, etc.). While major outlets with specialized departments for Japanese currency offer reliable listings, considerations for shipment and customs costs are necessary. Purchases via flea market apps and online auctions are highly risky in terms of authenticity and are not recommended. There is always a reason for "Keichō Chōgin that are too cheap". For detailed information on appraisal and valuation use before purchasing, check Guide to Sources and Methods of Acquisition for Old Coins.