1929 Standing Liberty Quarter Dollar. type 2 If there is a mint mark it would be just to the left of the liberty's right foot, which is totally worn away along with the last vertical star. See pictures: https://www.usacoinbook.com/coins/quarters/standing-liberty/
Considering how worn the coin is I am pleasantly surprised that it still has a clear date. The date is often totally gone on SL quarters by the time they get to this point.