Please check your coin again. The first Sacajawea dollars were released in 2000. 1979 $1 coins carry a picture of Susan B. Anthony.
twenty-five dollars
There were no Sacajawea gold dollars minted in 1990.
Circulating Sacagawea dollars are only worth face value. Ditto for the new Presidential dollars.
There is a mistake in your question. The Sacajawea dollars were not minted until 2000, so there would be no 1979 Sacajawea dollar. However, if you meant a 1979 dollar coin, those are Eisenhower dollars and are typically worth face value unless they are in exceptional condition.
Dates are also needed, post new question
They're not silver, they're brass. The last silver dollars were made in 1935. In any case Sacajawea dollars are not rare at all, and any that you get in change or from a bank are only worth face value.
a dollar
None of the Sacagawea dollars regardless of date or mintmark struck for general circulation have more than face value. Only proof and uncirculated collectors coins sold from the Mint have premiums
A dollar. Starting in 2009, the date was moved from the front of the coin to the edge, similar to the incuse lettering on the edges of Presidential dollars.
Sacajawea dollars aren't gold and they aren't plated. They're made of a metal called manganese brass, and the outer layers are mechanically bonded to a copper core. About a billion Sacajawea dollars were made in 2000 so unless your coin is either a proof or uncirculated one, it's still only worth $1.
None of the SACAGAWEA dollars regardless of date or mintmark struck for general circulation have more than face value. Only proof and uncirculated collectors coins sold from the Mint have premiums.
1 dollar