Gaudens double eagle

A Double Eagle is a gold coin of the United States with a denomination of $20. (Its gold content of 0.9675 troy oz was worth $20 at the then official price of $20.67/oz). The coins are made from a 90% gold (0.900 fine = 21.6 kt) and 10% copper alloy.

Although the "eagle"-based nomenclature for gold U.S. coinage is often assumed to be a nickname, the "eagle," "half-eagle" and "quarter-eagle" were specifically given these names in the Act of Congress that originally authorized them ("An Act establishing a Mint, and regulating Coins of the United States", section 9, April 2, 1792). Likewise, the Double Eagle was specifically created as such by name ("An Act to authorize the Coinage of Gold Dollars and Double Eagles", title and section 1, March 3, 1849).