Natural 11-12mm White Freshwater Cultured Flat Coin Pearl Sterling Necklace 18''. This beautiful necklace features natural 11-12mm white freshwater cultured flat coin pearls that are strung together in a beaded strand style. The lobster closure ensures a secure fit, making it perfect for any occasion such as engagement, Mother's Day, Christmas, graduation, anniversary, Father's Day, birthday, christening, confirmation/communion, or Valentine's Day.