Have you had the gold tested by a jeweler? Bad sellers will sometimes sell gold-plated that is marked as solid gold. If they are solid 18K, then that would probably mean the pearls are good quality and real.
I can't tell if I see any orient or not based on your photos. Can you take a photo on a white paper towel in natural light, but not directly in the sun?
Do you see any imperfections at all?
What does the area of the pearl that is attached to the post look like? Can you give a photo of that, too?