An octagon-shaped coin has been produced by the United States Mint, as well as several other mints and a private issuer. Most coins are round due to straightforward production, machining efficiency, and everyday functionality. Octagonal coins represent deliberate and often symbolic departures from this norm for commemoration, differentiation, or cultural resonance.
What Octagon-Shaped Coins Have Been Issued?
Octagonal coins have appeared across different times and regions. One of the earliest octagonal coins produced was in India under the Ahom Kingdom between the 13th and early 19th centuries. Between the 16th and early 20th centuries, German states issued octagonal coins denominated in ducats, kreuzers, thalers, hellers, marks, and pfennigs.
Private mints in California, such as Moffat & Co. and the U.S. Assay Office under Augustus Humbert, introduced octagonal gold “slugs” and fractional coins during the Gold Rush. These were issued to address the chronic currency shortages faced by miners and merchants.
In 1915, the U.S. Mint issued the $50 Panama-Pacific commemorative gold coin in both round and octagonal forms. The octagonal version, encircled by dolphins, is the only official octagonal coin ever issued by the United States Mint. It was not the only official octagonal issue from the U.S. Mint, though. In 1925, the Mint struck the Norse-American Centennial Medal on an octagonal planchet, although it had no face value as a medallion.
From the early 1990s to the early 2000s, Chile issued octagonal coins in 1, 5, and 10 pesos. Periodically throughout its history, the nations of France and China have both issued octagonal coins, although few of these were intended for circulation. Other world mints have issued octagon-shaped coins as patterns, commemoratives, and tests, and these were not intended for circulation, either.
Technical and Practical Aspects of Octagonal Coinage
Octagonal coins have rarely been adopted for high-volume issuance, as their production entails distinct technical challenges. The sharp angles increase die wear, complicate blank preparation, and make the coins more vulnerable to point damage in circulation.
While advances like CNC (computer numerical control) engraving and laser cutting have made complex shapes easier to produce and finish, most non-round coins today are relegated to collectible or commemorative roles. Circulation examples, such as The Royal Mint’s recent issues of heptagonal 50p and 20p coins, demonstrate that with careful engineering, polygonal shapes can work on a national scale. Despite modern advances, however, the structural efficiency of the circle remains unrivaled for everyday coinage.
Coin Shape and Public Perception
Coin shapes fall into distinct classes, including round, polygonal (e.g., octagonal, heptagonal), scalloped, holed, and others. Novelty shapes, such as hearts and maple leaf designs, also populate the modern landscape. Among collectors, polygonal and non-round coins can elicit both excitement and debate. Some view them as innovative additions, but for others, inclusion in competitive registry sets or recognition by major grading services determines their legitimacy. The broader public may see them as curiosities, yet their distinctiveness ensures ongoing interest and conversation.
Though round coins will likely remain dominant, octagonal and other varieties of shaped coins endure as compelling reminders that currency reflects not just commerce, but culture, identity, and innovation. Their technical rarity, historical symbolism, and collectability ensure their ongoing presence in numismatic study and connoisseurship, demonstrating that the story of money is also a story of creativity and meaning.
