What This Coin Looks Like (Obverse, Reverse, Mint Mark Location, Special Features, etc.): There are two major versions of the 1971-S Eisenhower Dollar - both of them have a silver-clad composition with a 40% silver content. The common version is the 1971 Brilliant Uncirculated silver Eisenhower Dollar (as depicted above) which came in the blue pack/envelope with a blue seal ("Blue Ikes"). These were special mint condition coins sold to collectors.
The other version is the 1971 S Silver Proof Eisenhower Dollar which came in proof sets or brown boxes with a gold eagle seal ("Brown Ikes") - only 4265234 of these mirror-like silver proof coins were produced. An example of the proof version is depicted below:
Coin Value Chart: Typical Coin Prices, Values and Worth in USD based on Grade/Condition