Pearls need humidity and should be stored in a cloth bag to keep them from drying out or becoming scratched. You may gently wipe pearls with a soft damp cloth to clean them. Basic precautions for gemstones are to avoid excessive impact against hard surfaces, extreme temperature changes and contact with perfumes, cosmetics and household cleaners. Ultrasonic cleaning is not safe for many gemstones. A soft damp cloth for gently cleaning your gemstones is highly recommended.