Coral jewelry is extremely fragile as it is made of the calcified remains of microscopic animals. It can be polished to a beautiful shine and is often set in a bezel in order to protect the edges of the piece. You must be extremely careful when cleaning coral jewelry so that you do not scratch the surface or actually wear away at the coral itself.
Wet the soft cloth with warm water. Do not use hot water as extreme temperatures of either hot or cold can damage the coral. You should soak the cloth in the warm water until it is saturated.
Wring out the cloth. Make sure that the cloth is barely damp. By this time it will probably only be slightly warm, which is fine.
Gently wipe the surfaces of the coral jewelry. Do not scrub or press down on the coral as you can easily wear away the smooth, polished top with excessive cleaning. It is better to clean coral regularly but not aggressively in order to avoid having to scrape or scrub at ingrained dirt.
Avoid touching the coral with any cleaner. You will probably need to clean the setting from time to time. When you do so, be very careful to only touch the setting with the jewelry cleaner. If it is possible to just clean the setting with warm water, do so. However, sterling silver settings and other gemstones may occasionally require more attention.
Clean the setting around the coral with a soft brush. Do not brush the coral. Use the soft brush very carefully to work out dirt that is packed in crevices of the setting. Use a fingernail under the soft cloth to clean around a bezel rather than the brush to make sure that you do not scratch the coral.
Coral jewelry should never be placed in an ultrasonic cleaner. Nor should it be cleaned with anything other than plain water.