The coin in question is an 1866 Seated Liberty Dime, an iconic piece of American numismatic history crafted by the renowned designer James Barton Longacre. This particular dime is notable for its production type, being a Proof coin, which indicates it has been struck with high precision and care, intended for collectors rather than for circulation. This coin has a denomination of 10 cents (10¢) and is composed of 90% silver and 10% copper, which was standard for U.S. coinage of this time, contributing to both its aesthetic appeal and intrinsic value. It has a diameter of approximately 17.9 mm and weighs 2.48 grams. This specific 1866 Seated Liberty Dime does not carry a mint mark, signifying it was produced at the main mint without any additional identification. Its mintage is notably low, with only 725 pieces struck, making it a rare find amongst collectors. The coin features a reeded edge, a common characteristic in U.S. coinage designed to prevent coin clipping and counterfeiting. As a product of the United States of America, this coin not only serves as currency but also as a testament to the craftsmanship and historical significance of American minting practices during the 19th century. Given its rarity and the condition that is often attributed to Proof coins, the value of this particular 1866 Seated Liberty Dime can vary significantly in the marketplace, appealing to both serious numismatists and casual collectors alike.