25 Huge 15mm Seductive Pearl Disc Beads - Heavy!Price is per 25 beads of these massive lustrous pearls. Most are the largest size of a big 15mm x 6mm . 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 shell building, nacre. To cultivate a pearl, farmers