The pearl is from a food oyster, not a pearl oyster. Though this forum gets almost monthly finds of this kind of pearl from a food oyster, and everyone wonders how much they are worth, they are worth nothing but the good story you get out of it.
Actually, this is the first wearable one I have seen!
If I found it, I would drill it at the top, and thread a leather tie through it and wear it. It has grown on me since my first comment. It actually has an earthy-toned, kind of fall-toned jewelry look. Or if you were to put a bail on it and medium weight chain. Or find a special stand or display box, if you don't care for earthy jewelry.
I doubt you will ever see such a thing again.
If you sell it, it is worth exactly what the buyer paid for it, because there is zero market for food pearls.
You will never find more qualified people to look at your pearl either. This has been a big, free, service to you and saves you from taking it to a jewelry store for more rejection.