Metal Composition: 91.67% Gold - 3% Silver - 5.33% Copper
Diameter: 32.7 mm
Mass / Weight: 33.931 grams
What this coin looks like (obverse, reverse, mint mark location, special features, etc.): The 2006-W "Reverse Proof" American Gold Eagle was the first US coin of its kind ever made. Only 10000 of these coins were produce - so they are very rare and valuable. This coin was produced as part of a 3-coin gold eagle set to commemorate the 20th anniversary of the American Gold Eagle series (which started in 1986). The 3-coin set included a burnished uncirculated gold eagle (the first time the "W" mint mark appears on an uncirculated gold eagle) - and the set also includes a proof gold eagle and of course the reverse proof gold eagle. This set originally had a cost of $2610.
The reverse proof was produced at the West Point Mint using a highly innovative and technologically advanced minting process - which resulted in a coin with a frosty satin background field (like normal uncirculated gold eagles) but the details and designs have brilliant mirror-like features. This coin also bears the "W" mint mark.
Coin value chart: Typical coin prices, values and worth in USD based on grade/condition