Amber
Use warm soapy water and pat dry with a soft cloth. Do not expose it to heat, as it will melt. Brushes, commercial cleaners and chemicals should be avoided and it's best not to soak amber.

Corundum
Rubies and sapphires are very resilient, so it's important to take care of the metal they are set in. Do not put badly fractured gems, black star sapphires or oiled rubies in chemical cleaners.

Diamond
Ammonia based and ultrasonic cleaners could remove greasy build up, as will soaking in alcohol. Do not put diamonds with fractures near heat or into ultrasonic cleaners.

Gold
Use warm soapy water or alcohol to dissolve tough dirt. Do not use ammonia, as it can turn soldered joints dark. Mercury turns gold white.

Emerald
Clean with a soft cloth, warm water and a soft brush. Most natural emeralds have inclusions that make them vulnerable, and more brittle stones can be re-oiled every few years if necessary. Do not use an ultrasonic cleaner or steamer.

Opal
Do not soak, bleach or wet doublets and triplets. You can clean opal with a moist or soft dry cloth. Store in a padded bag, and avoid sudden temperature changes and chemicals.

Pearl
Wipe with a soft dry cloth or chamois. If they must be washed, always rinse, pat dry and lie on soft cloth. Do not allow contact with perfume, hairspray, alcohol or heat, and do not rub them together.

Platinum
Use alcohol and a soft toothbrush to remove dirt, and do not allow iodine or Mercurochrome to come into contact with platinum, as they both will stain.

Silver
Clean regularly with a soft cloth, but do not use ammonia. Some foams and liquids can remove a layer of silver, while toothpastes and abrasives can scratch.

Tanzanite
Vulnerable when set in rings and likely to fuse when exposed to extreme heat, these stones should only be washed in warm soapy water and dried with a soft cloth. Do not use mechanical cleaners.