All Franklin half dollars were made of 90% silver, but 1951 is not a rare year. In lower grades the coin's value is mostly determined by the value of the silver it contains, about 0.36 times the current price of an ounce of silver.
Look on the back of the coin to see if there's a small mint mark letter just above the Liberty Bell. It may be blank or there may be a D or S.
Numismedia lists the following approximate retail values as of 10/2011:
No mint mark (Philadelphia):
Almost no wear - $18.60
Uncirculated - $19.20 to $2340.00 depending on quality
"D" mint mark (Denver):
Almost no wear - $19.10
Uncirculated - $26.40 to $1200.00
"S" mint mark (San Francisco):
Almost no wear - $19.10
Uncirculated - $26.40 to $1920.00
DISCLAIMER: The retail values quoted are the best available as of the date shown, but may vary significantly due to changes in the precious metals market. Also the wholesale (buying) price of a coin will be less than the selling (retail) price. A reputable coin dealer will be able to give a more accurate valuation based on inspection of the coin.
View the links below for full statistics and other values of the coin for different conditions.
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.
It has a metal value of about $10.
Value is for the silver about $2.50
a half dollar
The US didn't strike any half dollars in 1804.
A U.S. half dollar dated 1953 or 1952 is a Franklin half dollar. If it shows any wear, the value is only for the silver, about $10.00. The coins are very common.
A US half dollar with a date of 1983 is a Kennedy half dollar not a liberty half dollar.The coin has no silver and most are only face value.
In average circulated grades the value is less than one dollar.
The value of a US 1964 half dollar in circulated condition is around $10. in uncirculated condition they are worth around $16.
The Franklin half dollar was produced between 1948 and 1963. Please check your coin again. For the value of a 1937 LIBERTY half dollar, see the answer on WikiAnswers for the question "What is the value of a 1937 US half dollar?"
You have a Franklin half dollar - a 1957 proof coin is worth around $25.00.
A US Kennedy half dollar dated 1969 is only 40% silver with a value of about $2.00.
If the coin is a US Kennedy half dollar dated 1974 it has no silver in it and is face value.
The value of a 1966 Canadian silver half dollar is about 8.50 US dollars. In the case of the rare small bead variety, the value is between 1,000 and 2,000 US dollars.
The U.S. half dollar has never been made of gold. What you probably have is a gold-plated 1979 half-dollar. It's not really worth much above face value.
No US bills were printed with a 1951 series date. Please check again and post a new question.
Please check your bill again and post a new, separate question. No US bills are dated 1951.
The US didn't print any bills with that date.
All US half dollars from 1964 to date have Kennedy on them, your 1995 half dollar is face value.
Look at the back of the coin for "HALF DOLLAR" no US dollar coins were struck after 1935.
The 1943 Walking Liberty half dollar is the high mintage of the series with an average value of $5.00 to $8.00 in circulated condition.