The coin in question is a 2005 San Francisco minted Sacagawea Dollar, which is part of the United States dollar series. This particular coin features a stunning proof finish, characterized by its highly polished surface and detailed design, making it a collectible item for numismatists and coin enthusiasts alike. Manufactured from manganese-brass, this one-dollar coin has a diameter of 26.5 millimeters and weighs 8.07 grams. It was produced in a limited mintage of 3,344,679 pieces, which adds to its potential value for collectors. The coin does not display any height or width dimensions that would typically be measured in a three-dimensional context, indicating it is primarily evaluated by its diameter and weight. The Sacagawea Dollar itself honors the Shoshone woman who played a crucial role in the Lewis and Clark expedition, and the design reflects her image alongside a soaring eagle, symbolizing freedom and the exploration spirit of the early 19th century. Given its proof quality and the San Francisco mint mark "S," this coin not only represents the artistry of American coinage but also has significant value in terms of collectibility, especially for those focused on modern commemorative pieces within American currency.