Pearls can scratch so be sure to protect them from direct contact with the other jewellery and other sharp objects that could scratch them.
Do not use chemicals on or around your pearls such as hairsprays, perfumes, detergents, cosmetics, chlorine, etc. Acidic compounds are horrible for pearls and can cause a slow but damaging erosion to the pearl.
To clean your pearl, mix a solution of water and mild dish soap in a small bowl. Agitate the water with a soft toothbrush and lightly scrub the setting and pearl. Rinse with fresh water and dry with a soft cloth. Then take a cotton swab of Q-tip and apply some olive oil to the surface of the pearl. This enhances pearl lustre.
Pearls also contain protein and water, so do not store pearls in airtight containers or safes as they are subject to dehydration and cracking. It is advisable to moisten them from time to time.
Salt water and fresh water are fine for pearls. Chlorinated (acidic) water such as in a pool is very bad for pearls.
Do not be shy to wear your pearls in various settings. Pearls love to be worn, so enjoy them.