Because they are an organic gem comprised of calcium carbonate, pearls require more specialized care than most other gems materials. They are particularly subject to deterioration from contact with chemicals, including components in household cleaners, perfumes, cosmetics and hair care products of all kinds.
Pearl strands should be stored separately from other jewelry because the surface of a pearl is soft and easily scratched by other gems. A silk bag, velvet-lined box or pearl folder or a satin-lined leatherette envelope with snaps to hold a strand in place–are all good places to store pearls.
NEVER store pearls in a plastic bag. Some types of plastic emit a chemical that will cause the surface of your pearls to deteriorate.
Lay the strand flat on a clean soft cloth or towel. Make a mild solution of soap flakes (I use Ivory soap flakes) and warm water, and apply with a new pure natural bristle complexion or manicure brush, scrubbing gently. Being careful to support the strand so as not to stretch the thread, turn the necklace over and repeat. To rinse, submerge the strand in cool water flush with cool tap water for a minimum of five minutes. Carefully remove the strand from the water and lay it on a fresh towel to air dry. Don’t move it until it is completely dry.