It's not an official US coin. The only $1 coins made in 1979 were small copper-nickel dollars depicting Susan B. Anthony. You may have a privately-made commemorative or something similar but without more information it's not possible to provide an evaluation.
Please post a new question with more information including the coin's size, any wording on it, etc.
How much is a portrait of Lyndon B. Johnson worth?
Post new question with the date of the coin.
The Andrew Johnson dollar coin is worth exactly one dollar.
There's no silver in it, and it's worth one dollar.
1896 silver dollar is worth how much?
how much is a 1924 silver dollar worth
a dollar
A dollar
It depends greatly on the year, early silver dollar proof dollars can be worth several thousand dollars, modern silver dollar proofs of common dates might be worth $20 or so for silver scrap.
how much is a 1799 silver dollar worth
A Washington silver dollar, believe it or not.
One dollar.