Big dollar coin it says 1oz fine silver What is it worth?

You need to be much more specific. If you have a $1 gold coin from the 19th century, please post a new question with its date, a description of its design (there were two different styles) and its mint mark if you can find one on the coin's reverse.

If you have a modern Sacagawea or Presidential dollar, remember they're not real gold regardless of any of the urban myths you may have heard. They're made of brass and are only worth face value. If you were to try to melt one all you'd have is about a dime's worth of scrap brass.