Overview and Historical Background of the Tōshisen Coin
The Tōshisen (当四文銭) is a large coin with a hole, valued at four mon per piece. It circulated as an important currency that supported Japan's monetary economy from the mid-Edo period to the end of the Edo period. As a high denomination following the one-mon coin "Kan'ei Tsūhō (寛永通宝)" which began minting in the 13th year of Kan'ei (1636), it made its presence felt. With a diameter of approximately 28mm, it was typically made of copper, weighing about 6–7g, making it slightly larger and heavier than the standard one-mon coin (approximately 24mm). The wave pattern cast on the back is its most significant visual feature, distinguishing it clearly from one-mon coins. The standard "eleven waves" pattern varies in numerous ways. In the daily transactions of common people, it contributed to simplifying high-value payments and change making. Particularly during the economic turmoil of the late Edo period, its role became even more significant. As explained in Introduction to Anezuri Coins (Kan'ei Tsūhō, Tenpō Tsūhō), the Tōshisen is an indispensable part of Japan's coinage history.
Variety of Materials: Transition from Copper, Brass, to Iron
Throughout its long minting period, the Tōshisen was made from various materials. The initial coins were copper-made "Kan'ei Tsūhō Ha-Nami" coins, minted around the 8th year of Kanbun (1668). These are characterized by their reddish hue and are commonly seen. Subsequently, after Genbun 1 (1736), brass (yellow brass) four mon coins appeared. Brass, an alloy of copper and zinc, is notable for its golden color and resistance to rust, with many well-preserved examples available. This change was influenced by the bakufu's financial situation and metal resource procurements. From Bunkyū 2 (1862), during the fiscal crisis and with the introduction of Western casting techniques, a large number of iron four mon coins were minted, known as "Bunkyū Eiho Iron Coins." These are grayish-black and attracted by magnets. Differences in materials are explored in detail in Types and Market Prices of Kan'ei Tsūhō and Bunkyū Eiho Collection Guide.
Appeal and Market Evaluation of Brass Four Mon Coins
Brass (yellow-brass) Tōshisen coins, known as "Brass Four Mon Coins," are especially popular due to their unique golden shine. This alloy of copper and zinc is not only visually appealing but also durable. They are more resistant to rust compared to copper coins, with less occurrence of verdigris, resulting in many well-preserved examples. This characteristic makes them highly attractive to collectors. Coins that retain excellent condition from the time of minting are especially valued for display. Bunkyū-period mass-minted brass coins are relatively accessible, but focusing on detail craftsmanship and patina (antique color) adds depth to the collection experience. The brilliance of brass is a crucial factor in judging the "condition," one of the Factors Determining the Value of Old Coins. Only confirmed records (including event, lot, source URL, and confirmation date) are listed as market records for individual prices and auction examples.
Variations of the Back Wave Pattern and the Deep Study of Authentication
The wave pattern on the back of the Tōshisen is at the core of its identification and classification. The "eleven waves," standard with 11 waves, gets its name from the number of waves, but in reality, the number of waves, their depth, shape, and even the rolling direction show diverse variations. For example, some have deeply and clearly carved waves compared to shallow and indistinct ones. These differences primarily arise from the mint, casting period, or mold wear. Certain mints (e.g., Mito coins, Kameido coins) exhibit unique wave expressions, forming advanced collection points. Identifying subtle differences in wave patterns is not only for classification but also acts as clues to infer where and approximately when the coin was minted. Studying these subtle differences is essential for understanding the concept of "varieties" in Old Coin Types and Classification Systems, and is one of the joys of collecting Tōshisen.
Diversity in Coin Variants and Mints
The text surfaces of Tōshisen, meaning the kanji "寛" (Kan), "永" (Ei), "通" (Tsū), "宝" (Hō), exhibit differences in calligraphy that vary by mint and period. Though they may look similar at first glance, there are subtle differences in stroke thickness, dots, balance, and overall character shape, which intrigue collectors. For instance, some mints feature strong brushstrokes, while others use more delicate Kaisho script. These differences in calligraphy serve as crucial clues, indicating where the coin was produced. Local mints had their distinct style, illustrating the diversity within the Edo period monetary system. In particular, "rarities" or "unique coins" departing from standard calligraphy can be highly valued in the market. Though less studied than one-mon coins, through detailed observation and comparison, there’s potential for new discoveries, making this field highly appealing to advanced collectors.
Mother Coins and Circulating Coins: Differentiation and Rarity Value
In the world of ancient coins, a mother coin is the prototype for making a mold for circulating coins and can be exceptionally valuable due to its rarity. Tōshisen mother coins are no exception. They are slightly larger than circulating coins (by about 0.5–1mm), with deeply and vividly carved characters and wave patterns. Additionally, the rim finish is meticulous with fewer burs, exhibiting an overall exquisite craftsmanship. Mother coins tend to weigh more than the standard circulating coins (copper weighing around 6–7g). This is because they were made thicker and more carefully to create precise molds. In the market, mother coins can sometimes be traded for tens of thousands to hundreds of thousands of yen. There are occasional cases where mother coins are mistakenly listed as regular circulating coins at low prices, and with deep knowledge and discerning eyes, it may lead to unexpected discoveries. The discovery of a mother coin symbolizes "rarity," a key factor in Factors Determining the Value of Old Coins.
Key Points in Authentication: Material, Condition, and Authenticity
Authentication of Tōshisen involves identifying the material, evaluating the condition, and distinguishing genuine from counterfeit. First, determine the material by combining ① color (copper: reddish-orange, brass: golden, iron: grayish-black), ② magnet test (iron is magnetic, copper and brass are not), and ③ weight measurement (iron is heavier even in the same size). Specific gravity measurement helps in accurately determining the material. Evaluating the condition involves the wear level of characters and wave patterns, surface scratches, and beauty of the patina. Brass coins are more resistant to rust and often remain in relatively good condition, whereas iron coins are prone to rust. Understanding appropriate Coin Grading Standards allows for objective evaluation. Distinguishing genuine items requires focusing on casting marks clarity, writing strokes, wave pattern preciseness, and weight. Modern sophisticated counterfeits and altered items exist, necessitating careful observation for unnatural luster or casting inconsistencies. Refer to Counterfeit and Forgery Detection Guide for cautious judgment.
Proper Storage and Maintenance of the Tōshisen Coin
To keep Tōshisen coins in good condition over the long term, appropriate storage and care according to the material are essential. For copper coins, since verdigris is prone to develop in humid environments, it is recommended to store them in sealable coin capsules or slabs with desiccants like silica gel. The ideal humidity level is below 50%. Brass coins are more stable than copper and less susceptible to rust, but exposure to direct sunlight or sudden temperature changes should be avoided as it may cause discoloration. Iron coins are the most susceptible to rust and require special care. A thin layer of anti-rust oil should be applied, and they should be stored in sealed containers with desiccants. If rust progresses, it can significantly reduce value. For any material, using polishes or metal cleaning agents is strictly prohibited. It can damage the surface's patina, significantly lowering the coin's value. If dirty, it's wise to gently wipe with a dry, soft cloth. Refer to Coin Storage and Maintenance Guide for detailed methods to protect your valuable collection.
Getting Started with Collection and Market Value
Tōshisen coins, thanks to their affordable price range, are among the best coins for beginners in Ane-Coin collecting. Standard pieces can be easily acquired for 100–500 yen, allowing enjoyment of differences in material and wave variations. Their large size and striking appearance provide satisfying fulfillment as one's first ancient coin. A recommended first step is to gather one piece each of copper, brass, and iron, and to physically compare these differences. Next, seeking aesthetically clear wave patterns or specifically styled markings enhances the depth of collection. Brass pieces in excellent condition are particularly popular, and may be valued at several thousand yen depending on their state. As an investment, significant price appreciation for general circulating coins is unlikely, but rare mother coins, early mint special editions, or coins with exceptionally unique calligraphy can hold a value of several tens of thousands of yen or more. Collecting Tōshisen can be prudently started from reliable sources as guided in Ways to Acquire and Purchase Old Coins.