It's a fantastic question that touches on a common and understandable point of confusion in the coin world. While many people call it a "silver dollar" because of its color and history, the 1979 dollar coin you have is actually a Susan B. Anthony dollar, and it contains no silver. These coins are made of a copper-nickel clad, just like modern quarters and dimes. This is the most important factor in its valuation, as its worth isn't tied to the fluctuating price of precious metals.
For the vast majority of 1979 Susan B. Anthony dollars, the value is simply their face value: one dollar. Hundreds of millions were produced at the Philadelphia (P), Denver (D), and San Francisco (S) mints, making them very common. If you have one that has been used in circulation, it is almost certainly worth just a dollar. Even a standard, shiny uncirculated coin that you might get from a bank roll is typically only worth a couple of dollars to a collector.
However, the real excitement for a 1979 dollar lies in a specific, rare variety that is absolutely worth looking for. You'll want to carefully inspect any 1979 dollar with a "P" mint mark (for the Philadelphia mint). A small number of these were struck with what is known as a "Wide Rim" or "Near Date" variety. On these valuable coins, the date "1979" appears much closer to the coin's rim than on the common "Narrow Rim" version. If you happen to have a 1979-P Wide Rim dollar, its value can jump significantly, often starting around $5-$10 in circulated condition and climbing much higher for uncirculated examples. So, while most are worth a dollar, it's always worth that closer look to see if you have the rare and valuable exception.
