You might want to post a scan instead of this blurry picture.
It would not only be a question of identifying the stamp but also of determining whether it is genuine and its quality.
Furthermore, it would be helpful to explain what makes you think it might be valuable.
The commonest mistake made by people is to see an outrageous asking price on Etsy or
ebay for a common stamp that is worth as much as it was issued for.
If you do not have access to a scanner, make a picture, preferably against a black background, by laying down the stamp and laying down the phone on a raised flat surface. E.g., stack a few cereal cartons and lay your phone to make a sharp picture. Using stairs may also work.