Online listings should explicitly detail these factors, as established by the GIA (Gemological Institute of America) :

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:

Beyond the body color (white, black, gold), look for the "overtone"—the subtle hint of pink, green, or silver that appears when light hits the surface.

Perfectly round pearls are the most valuable, but "baroque" (irregular) shapes are popular for unique, modern designs.

Look for descriptions regarding "blemishing." While small natural imperfections prove a pearl is real, the surface should be mostly smooth and free of major cracks or pits.

Look for consistent feedback on platforms like Google or Trustpilot regarding luster and matching. 2. Know the 5 S's of Pearl Quality

If every pearl in a strand looks 100% identical in shape and color, they are likely synthetic.

Pearls are measured in millimeters. Standard strands are usually 7.0–7.5mm; larger pearls (over 10mm) increase significantly in price. 3. Match the Pearl Type to Your Budget