Not silver. The only nickels that ever contained silver were the famous "war nickels" minted during WWII when nickel was a strategic metal. All other nickels are made of an alloy of 75% copper and 25% nickel.
Bottom line - you have an ordinary nickel worth 5 cents.
If you found it in change your nickel is only worth face value. US nickels made from 1866 to mid-1942 and from 1946 to the present are made of a copper-nickel alloy, not silver. In fact, no circulating US coins have contained any silver since 1969.
The only years silver was used in US nickels was 1942-1945, the coin is face value.
Your nickel contains no silver. Only nickels made from 1942-1945 contain silver. See the related question below.
That's a silver war nickel, containing 35% silver, and it's worth at least $2.
As of 07/2010 a 2000 silver proof set retails for about $35. Your proof set's package should say that it's a "Prestige" set. Anything else contains copper-nickel coins, not silver and sells for about $14.
Copper-nickel, not silver. The only nickels that ever contained any silver were the famous "war nickels" made from 1942 to 1945, when silver replaced nickel metal because nickel was needed for the war effort.
The only US nickels to contain silver are those minted during WWII. A 1959 nickel in uncirculated condition might go for 25 cents.
That is known as a "war nickel" to save nickel for the war effort, the US government replaced some of the nickel in the nickel with silver. At the time of writing the silver content in them is around $1.70. The reason for the mintmark over the Monticello was that the idea was that people would know they contained silver.
US quarters were not made of silver in 1965, but rather of copper-nickel. The last silver quarter made for circulation in the US were produced in 1964.
A 1902 Liberty Head nickel is common, in average condition value is a dollar or two for most coins. No US nickel was made of silver until late 1942 through 1945 these are the "War Nickels" and had 35% silver in them. From 1946 to date they are copper- nickel.
All circulating dimes dated 1965 and later are made of copper-nickel, not silver.
It's not silver, but it should be worth from about a dollar in Good condition and up to $70 if uncirculated.