Please post a new, separate question with the coin's date and actual denomination.
First, the term "minted" describes the process by which a coin is made so an "unminted" coin by definition is one that hasn't been made yet, and so it can't exist.
Second, JFK is on the HALF dollar. The last US silver dollars for circulation were made in 1935.
If you check the back you'll find that you have a halfdollar. There has never been a US-issued Kennedy silver dollar.
About $15.00, retail.
If you mean a 1998 Kennedy half dollar, the coin has no silver in it and is worth face value.
It isn't silver. It is worth 50 cents unless it is a proof coin.
Most 1966 Kennedy halves are only valued for the silver(40%) they contain. Currently about $2.35
A 1969 silver Kennedy half dollar is worth $5 inn perfect condition. The value of the silver is worth $2.87.
A 2002-S silver proof Kennedy has an average retail value of $18.00.
If you check the back you'll find that you have a halfdollar. There has never been a US-issued Kennedy silver dollar.
The 1969 Kennedy half dollar is only 40% silver with a value about $3.25
About $6 for its silver content
The coin is 40% silver and has a value of about $2.00 only for the silver.
If the coin is a 1996-S Silver Proof Kennedy Half dollar, average retail value is $12.00 to $15.00
If the coin is a US Kennedy half dollar dated 1974 it has no silver in it and is face value.
The coin has no silver and is just face value, spend it.
Please, turn the coin over and look at the denomination on the back. It's a HALF dollar, not a dollar. The 1964 Kennedy half is a 90% silver coin, but very common. The value would be only for the silver, about $15.00 as of 9-1-11.
It has no silver and is just 50 cents, spend it.
About $15.00, retail.