You have a very common error called a "filled die" error. It happens when grease or other crud gets into one of the little recesses in a coin die that forms the letters and numbers.
Unless the number is entirely missing, it's unlikely to be worth more than a small amount above face value, if that.
25 cents.
25 cents
It's a common circulation coin worth face value only.
It is worth face value unless it is uncirculated then it will be worth around 50 cents.
25¢, like nearly every quarter minted since 1965.
i would say about 8 dollars to 25 cents
If the back of your coin has a picture of an eagle landing on the moon and a very severe-looking woman on the front, it's called a Susan B. Anthony dollar. All of the ones you'll find in change are worth just a dollar. Anthony dollars were issued for circulation in 1979, 1980, and 1999 but were failures because they were almost identical in size and color to a quarter, as you noted.
Trust me, it is not authentic. The 1979 dies were destroyed 13 years before the 1993 dies were made.
No one will be able to answer that question without seeing a picture The worth is determined by the condition and the mileage and if it has any parts missing from it.
Eischied - 1979 Who Is the Missing Woman 1-8 was released on: USA: 30 November 1979
25¢, like nearly every quarter minted since 1965.
The Halloween That Almost Wasn't - 1979 TV was released on: USA: 28 October 1979