Take a look at PCGS, or NGC websites for current values. Otherwise it is worth what the market will bear.
The American Eagle Gold Bullion coins with the denomination of $5 are 1/10th ounce of pure gold. Current market value is about $163.00.
1999 wasn't a really rare issue of the American Silver Eagle bullion coins. Depending on condition, you can most likely add a dollar or two to the value of silver contained in the coin. At the time of writing, sight unseen, I would estimate it to be worth around $30 depending on the grade with the bulk of that value coming from the 1 ounce of silver the coin is made with.
5-19-11>> The coin is actually an American Silver Eagle bullion coin that is made from one ounce of .999 pure silver. It's value is tied to the spot price of silver at the time of sale, which is $35.13 today
A 1999 American Eagle gold bullion coin is 1/4 ounce of pure gold, the value goes up and down with the spot price of gold during market trading. As of 10:05am 3-17-11 value is $350.20
It is worth whatever the gold price is. I'm assuming you have a US 1 oz gold eagle. If you do indeed have a one ounce gold eagle it is worth whatever 1 troy ounce of gold is worth. At the time of writing your coin would be worth about $1350. However, the price of gold fluctuates on a minute by minute basis.
8-4-11>>> This is a American Silver Eagle 1 ounce bullion coin. It is one ounce of pure silver.
A "colorized" silver eagle has no numismatic collectible value, but it's still one ounce of silver that's worth about $30.00.
The American Eagle
If you mean a American Silver Eagle dated 2000, it's one ounce of pure silver.
A $5 American Gold Eagle bullion coin is 1/10th of an ounce of pure gold. The New-York market closed at $1691.60 per ounce, so the coin is worth about $169.16.
Current Circulation Coins: One cent - no correct other name, but often colloquially called a "penny" Five cents - "nickel" Ten cents - "dime" Twenty-Five cents - "quarter" Fifty cents - "half dollar" Dollar - "buck" Susan B Anthony dollar coins were often times called "Carter Quarters", large sized dollar coins including the Eisenhower dollar which contains no silver is often called a "Silver Dollar" and Sacagewea and Presidential Dollars are often called "Golden Dollars" even though they contain no gold and should be distinguished from the much smaller and older Gold Dollar (1849-1889) that was struck in real gold. Historical Gold Coins: $1 - "Dollar" $2.50 - "Quarter Eagle" $3 - "Three Dollar Piece" $4 - "Stella" $5 - "Half-Eagle" $10 - "Eagle" $20 - "Double Eagle" Historical Coins: 1/2 Cent - "Half-cent piece" 2 Cents - "Two-Cent piece" 3 Cents - "Three-Cent Piece" (often called "trimes") 5 Cents (when struck in silver) - "Half-Dime" 20 Cents - "Twenty-Cent Piece" or "double dime" Common Bullion Coins (Though these coins have a face value listed, their actual value because of the precious metals they are struck in makes their actual value much higher than their face value) $1 Face Value, 1 troy ounce of silver - "American Silver Eagle" $5 Face Value, 1/10 troy ounce of gold - "American Gold Eagle (1/10 ounce)" $10 Face Value, 1/4 troy ounce of gold - "American Gold Eagle (1/4 ounce)" $25 Face Value, 1/2 troy ounce of gold - "American Gold Eagle (1/2 ounce)" $50 Face Value 1 troy ounce of gold - "American Gold Eagle (1 ounce)" $10 Face Value 1/10 troy ounce of platinum - "American Platinum Eagle (1/10 ounce)" $25 Face Value 1/4 troy ounce of platinum - "American Platinum Eagle (1/4 ounce)" $50 Face Value 1/2 troy ounce of platinum - "American Platinum Eagle (1/2 ounce)" $100 Face Value 1 troy ounce of platinum - "American Platinum Eagle (1 ounce)" Less Common Bullion Coins (Again, these coins have a face value listed, however their actual value based on the amount of precious metals in them makes their intrinsic value much higher than their face value) 25 Cents Face Value, 5 troy ounces of silver - "America The Beautiful Silver Bullion Coins (5 ounce)" $50 Face Value, 1 troy ounce of gold (has an American Indian on the obverse) - "American Buffalo"
Current Circulation Coins: One cent - no correct other name, but often colloquially called a "penny" Five cents - "nickel" Ten cents - "dime" Twenty-Five cents - "quarter" Fifty cents - "half dollar" Dollar - "buck" Susan B Anthony dollar coins were often times called "Carter Quarters", large sized dollar coins including the Eisenhower dollar which contains no silver is often called a "Silver Dollar" and Sacagewea and Presidential Dollars are often called "Golden Dollars" even though they contain no gold and should be distinguished from the much smaller and older Gold Dollar (1849-1889) that was struck in real gold. Historical Gold Coins: $1 - "Dollar" $2.50 - "Quarter Eagle" $3 - "Three Dollar Piece" $4 - "Stella" $5 - "Half-Eagle" $10 - "Eagle" $20 - "Double Eagle" Historical Coins: 1/2 Cent - "Half-cent piece" 2 Cents - "Two-Cent piece" 3 Cents - "Three-Cent Piece" (often called "trimes") 5 Cents (when struck in silver) - "Half-Dime" 20 Cents - "Twenty-Cent Piece" or "double dime" Common Bullion Coins (Though these coins have a face value listed, their actual value because of the precious metals they are struck in makes their actual value much higher than their face value) $1 Face Value, 1 troy ounce of silver - "American Silver Eagle" $5 Face Value, 1/10 troy ounce of gold - "American Gold Eagle (1/10 ounce)" $10 Face Value, 1/4 troy ounce of gold - "American Gold Eagle (1/4 ounce)" $25 Face Value, 1/2 troy ounce of gold - "American Gold Eagle (1/2 ounce)" $50 Face Value 1 troy ounce of gold - "American Gold Eagle (1 ounce)" $10 Face Value 1/10 troy ounce of platinum - "American Platinum Eagle (1/10 ounce)" $25 Face Value 1/4 troy ounce of platinum - "American Platinum Eagle (1/4 ounce)" $50 Face Value 1/2 troy ounce of platinum - "American Platinum Eagle (1/2 ounce)" $100 Face Value 1 troy ounce of platinum - "American Platinum Eagle (1 ounce)" Less Common Bullion Coins (Again, these coins have a face value listed, however their actual value based on the amount of precious metals in them makes their intrinsic value much higher than their face value) 25 Cents Face Value, 5 troy ounces of silver - "America The Beautiful Silver Bullion Coins (5 ounce)" $50 Face Value, 1 troy ounce of gold (has an American Indian on the obverse) - "American Buffalo"
The value of these bullion pieces is normally based on one ounce of silver, which currently has a spot price of around $14.
If you mean a American Silver Eagle bullion coin dated 2001?. All ASE coins are 1 ounce of silver
It would depend on what type of American Eagle coin it was. An American Eagle one ounce silver coin would be worth silver spot price, which is just over $21 a the time of writing, a one ounce American Eagle Gold coin would be worth gold spot which is just shy of $1300. The spot prices for metals can be found on websites such as Kitco or by simply typing in Gold (or silver) spot price in Google or another search engine.
It's a 2000 one-ounce Silver Eagle bullion coin and as of today is about $18.00
7-4-11>>> The coin is actually an American Silver Eagle bullion coin that is made from one ounce of .999 pure silver.