Opal, Emerald and Turquoise -- Stones should never be put in to an ultrasonic cleaner or exposed to a high temperature cleaner. Opals can crack, emeralds can fracture and turquoise can destabilize.

Pearls - Fresh or Saltwater (and other organic materials including coral, amber, abalone, and cultured pearls should all be handled with special care. Wash them in warm water with a gentle degreaser, such as Dawn. Rinse gently and lay flat to dry. Don't expose them to...

Diamonds - keep them clean so they sparkle and have the prongs checked periodically to make sure your diamonds are secure.