The U.S. did not issue any gold coins honoring JFK.
If you have a half dollar with that date, it's an ordinary coin that's been plated for use in jewelry or sale as a "collectible". In any case it's only worth 50 cents.
If it's from Another Country, please post a new question with that information.
Turn the coin over and check the denomination on the back. It's a 50 cent piece, not a dollar. The U.S. did not make any dollar coins in 1968.
A serious collector would consider this a damaged coin worth only face value. Someone not quite so particular about originality might pay a couple of dollars for the novelty.
Four quarters! HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!
The usual advice when someone suggests cleaning a coin is to say NO, NEVER! because cleaning destroys a coin's collectible value. But 1967 Kennedy halves are valuable only for the small amount (40%) of silver they contain, so if you want to use a product like Tarn-X or similar, you won't harm its metal value. The coins are still common among collectors so the chances that you could sell it for more than its metal value are extremely low.
The value of a coin can vary greatly depending on where you take it to be appraised as well as its condition. In general this coin is valued at between 5 and 10 dollars as of September 2014.
With the date of 1979 the coin is a Kennedy half dollar, it's worth 50 cents.
A US half dollar with a date of 1979 is a Kennedy half dollar not a liberty half dollar. The coin has no silver and is only face value.
The coin is still in circulation and only a dollar.
50¢ Please look at the back of the coin. It's a HALF dollar. It's also made of copper-nickel, not silver.
The coin is a 1979 SBA dollar and it's NOT silver. The coin is still found in circulation and is just a dollar.
The 1979-D Susan B. Anthony dollar is still in circulation today, the coin is face value.
Kennedy is on the US half dollar (50 cent) coin and Lincoln is on the penny (1 cent) coin.
One dollar.
.50
No such coin. Kennedy is only on the half dollars. Starting In 1971, the dollar coins are Eisenhower dollars. The coin is just face value.
The coin is not a silver liberty dollar. It's a 1979 Susan B. Anthony Dollar coin and has no silver in it and the value is one dollar.
Check that coin again. Kennedy wasn't put on the half dollar until 1964.