Ensure the vendor offers a Certificate of Authenticity and a solid, risk-free return policy—ideally 30 days or more—so you can inspect the pearls in person.
If every pearl in a strand looks 100% identical in shape and color, they are likely synthetic. how to buy pearls online
Since you can't do the "tooth test" (rubbing pearls against your teeth to feel for a gritty texture), look for these visual cues in high-resolution photos: Ensure the vendor offers a Certificate of Authenticity