Check for slight surface imperfections and irregularities
Look for a soft, subtle luster rather than a mirror-like shine
Rub the pearls gently together; real pearls feel slightly gritty
Test the weight; real pearls are usually heavier than imitations
Examine the drill holes for clean nacre layers, not chipped coating
Feel the temperature; real pearls are cool at first and warm slowly
Compare shape and size; real pearls often vary slightly
Inspect under magnification for layered nacre structure
Try the tooth test; real pearls feel faintly rough against the teeth
Ask for a certificate from a reputable gemological lab