All 1964 JFK halves were struck in an alloy of 90% silver and 10% copper.
1964 was the only year for that composition. 1965-70 halves were struck in a 40%-silver clad composition. All circulating halves dated 1971 and later have no silver; they're made of the same copper-nickel "sandwich" metal used for dimes and quarters.
The 1966 Kennedy half dollar is made of 40% silver and 60% copper. It has a total weight of 11.5 grams and a diameter of 30.6 mm.
Not all silver. It is referred to as silver clad. Silver on both sides (40% by weight) with copper in the center. The semi-solid silver Kennedy half dollar stopped production in 1964, made of 90% silver. See the related link for more information.
All circulation halves minted since 1971 are made of the same cupronickel alloy "sandwich" as dimes and quarters. They are only worth face value. Since 1992 special collector editions have been struck in 90% silver. They cost MUCH more than 50¢ each, of course!
It's either not JFK or not a dollar. JFK is on the half dollar. President Eisenhower was on the dollar in 1972. Regardless, it's made of the same material as all other clad coins. It has outer layers of 25% nickel and 75% copper bonded to a core of 100% copper. If you have one in circulated condition, it is only worth face value.
No 1977 halves were struck in silver. It's also very difficult to tell by a coin's ring because clad coins are frequently irregular internally due to thickness differences that occur as the clad stock is rolled out. Look at the coin's edge. If it's copper-colored like the edge of a quarter or dime, you have an ordinary copper-nickel circulation half that's worth face value.
The Denver Mint made less coins.
You can cash in a 1964 Kennedy half dollar at a bank but they will only give you $0.50 for it. You would be far better off to sell it to a collector or a dealer. 1964 halves are made of 90% silver so they sell for around 10 times face value.
All circulating half dollars dated 1971 and later are made of copper-nickel, using the same "sandwich" composition as dimes and quarters.
1964 was the only year JFK halves were made of 90% silver alloy. The composition was changed to 40% silver clad in 1965, and to copper-nickel clad in 1971. A 1964 Kennedy Half Dollar contains .3617 ounces of pure silver. Multiply this by the spot price of silver to get the bullion value of the coin. At the time of this writing, silver was $16 an ounce, making a 1964 Kennedy Half Dollar worth about $5.80
The 1964 Kennedy half dollar is a 90% silver coin but so many were made only a very high grade uncirculated example is worth more than the silver in the coin. The silver value today is about $10.00.
Kennedy half dollar coins were made from 1964 to present, so, so far 46 years. They are still being produced.
The 1964 Kennedy half dollar is a 90% silver coin but so many were made only a very high grade uncirculated example is worth more than the silver in the coin. The silver value today (3-16-11) is about $12.00.
A 1964 Kennedy Half Dollar was actually composed of silver - its value in MS60 condition is: about 0.36 times the current price of silver. From 1965 to 1969, Kennedy Half Dollars were composed of 40% silver clad. All circulating halves with later dates are made of cupronickel and are only worth 50c
Yes, proof versions of the Kennedy half dollar were made. These will have the S mintmark.
Kennedy first appeared on the half dollar in 1964. This was the last year of 90% silver US coins, so this is the only year of 90% silver Kennedy half. 1965-1970 were 40% silver. All circulation-strike halves dated 1971 and later are made of copper-nickel, like dimes and quarters.
The bicentennial Kennedy half dollar is made of a copper-nickel alloy, special collectors coins were struck in 40% silver but they all have "S" mintmarks.
Not counting commemoratives and other coins minted for sale to collectors, the last half dollar minted in solid 90% silver was the 1964 Kennedy Half. 1965 through 1970 Kennedy halves have a copper core and 80% silver outer layers for a net silver weight of 40%.