History
The $5 half eagle was struck in 90% gold from 1839 to 1929 to a standard of 8.359 g, holding 0.24187 troy oz (7.523 g) of pure gold. It is one of the most widely collected classic US gold coins, and common dates trade at a premium over melt value.
Liberty Head half eagle (1839–1908)
The Liberty Head, or Coronet, $5 was designed by Christian Gobrecht and struck for almost 70 years at Philadelphia, New Orleans, San Francisco, Carson City, Charlotte, Dahlonega and Denver. Coins from 1866 onward carry the motto IN GOD WE TRUST above the eagle. Common Philadelphia and San Francisco dates from the 1880s–1900s are plentiful and trade modestly above melt, while Charlotte (C), Dahlonega (D) and Carson City (CC) mintmarks are far scarcer.
Indian Head half eagle (1908–1929)
Bela Lyon Pratt's Indian Head design is unusual because it is incuse: the design is sunk into the surface rather than raised, so the field is the highest point of the coin. It was struck until 1916 and again in 1929. The 1929 issue is rare because most of the mintage was melted after the 1933 gold recall, and the 1909-O is a key date.
Why collector value can exceed melt value
Melt value is only the floor. Classic US gold coins are no longer made, many were melted in the 1930s, and collectors pay for date, mintmark and condition. Even a worn common-date $5 usually sells for more than its gold content, and graded examples in high grades or rare dates can be worth many times melt. Before selling, check the date and mintmark and ask a coin dealer rather than a scrap buyer, and never clean the coin, which sharply lowers its collector value.
Do not confuse the historic half eagle with the modern $5 American Gold Eagle, a 1/10 oz bullion coin first struck in 1986. It contains 3.110 g (0.1 troy oz) of fine gold in a 22k alloy, less than half the gold of a classic half eagle, and trades close to its melt value plus a bullion premium.
Related: How much is a golden quarter worth? · Gold coin prices today