History
In 1986, Congress authorized the mint to begin producing both types of gold American Eagles. The legislation further stipulated that all of the gold used to make the coins must be mined in the U.S. Since the inception of the eagle coin program, over 13 million gold American Eagle coins have been minted. Furthermore, the U.S. government guarantees the weight, gold content and purity of every gold eagle.
Denominations
Both investment grade and proof gold American Eagles are minted in four denominations and sizes. The mint produces one-tenth ounce $5 coins, one-quarter ounce $10 coins, one-half ounce $25 coins, and 1-ounce $50 coins. Of the four denominations, the 1-ounce coin is the most popular among both investors and collectors. The coins are all legal tender, though their monetized amounts are symbolic, because on a per coin basis, the gold used to produce them is much more valuable.
Roman and Arabic
From 1986 to 1991, the year of issue on every gold American Eagle coin was expressed in Roman numerals. But in 1992, the mint switched date formats and began stamping the year in Arabic numerals, and has continued to do so ever since. So even if your Roman numeral reading skills are a bit weak, you still know that because the mint switched to Arabic numerals in 1992, that your Roman numeral stamped coins were minted earlier.
Reverse
Since the gold American Eagle program began in 1986, the reverse (back) of every gold eagle has had three constant features--the gold weight in ounces plus the words "Fine Gold", the image of an American bald eagle returning to its nest, and the monetized amount of the coin, such as "50 Dollars".
Gold Content
Contrary to popular option, the gold American Eagle coin is not made of pure gold. The coin is 22 karat gold, meaning its gold content is 92 percent. The gold in the coins is alloyed with 8 percent copper, which makes the metal slightly harder. However, the gold content is exactly the amount stamped on the reverse of the coin. So a $50, 1-ounce gold American Eagle contains an ounce of pure gold, plus the copper, meaning the coin actually weighs more than 1 ounce.
Proof Coins vs. Bullion Coins
Proof-grade gold American Eagle coins are struck individually, using specially polished dies, which gives each coin a mirror-like finish. After striking, gloved mint personnel encapsulate each coin in a sealed plastic holder. The coin is then placed in a velvet lined presentation box along with a certificate of authenticity. Bullion investment grade gold American Eagles, have a dull, more opaque finish and do not receive special packaging.