Most colored gems can be cleaned with warm water, mild dish soap (no
detergents) and a soft brush. A pulsed-water dental cleaning appliance and a
soft, lint-free cloth can also be used. Be sure to rinse your jewelry in a glass of
water to remove cleaning solutions since you risk losing loose stones – or even
an entire piece of jewelry - if you rinse directly in the sink.
 
Soft gems, such as pearls, on the other hand, can easily scratch. Use a new,
clean makeup brush and warm, soapy water to softly clean them. Lay a strand of
pearls on a towel to dry. The wet silk thread can stretch − and attract dirt − so
don’t touch your strand until it is completely dry. Pearls worn often should be
restrung once a year. (GIA)