Long Breathtaking 20mm Oriental Gold PearlsPrice is per (longer than usual) 16. 5 inch string of these massive pearls. About 22 to the string. Largest measures 20mm x 10mm x 8mm beautiful colour!. Cultured pearls Most pearls these days are cultured. These natural freshwater pearls occur in mussels for the same reason saltwater pearls occur in oysters. Foreign material inside a mussel can't be expelled. To reduce irritation, the mollusk coats the intruder with the same secretion it uses for