When silver comes in contact with air (oxygen) it oxidizes or turns an iridescent black.
When you are not wearing your silver chain, store in in a sealed plastic bag (keeping oxygen out).
To remove the black oxidation, rub the chain with a silver cleaning cloth.
Sterling Silver tarnishes if exposed to the elements for longer periods of time.
To prevent tarnishing and scratching, the jewellery should be kept in a pouch
in a cool, dry place. It is advisable to regularly polish the jewellery with an
untreated, soft cloth or a special silver cloth.
Soap, crème and make-up residues can be removed using an ultrasound device. Your local Jeweller should be able to clean it for you, sometimes free of charge.
The ultrasound device should not contain aggressive cleaning agents. For best
results, use water and a neutral detergent.
For standard commercial silver dipping baths, only silver jewellery dipping
baths must be used. In other words: no silver cutlery dipping baths and no gold
jewellery dipping baths!
One trick that I like is the Bi-Carb and aluminum foil trick; get a container and place a a sheet of aluminum foil into the container, then place your silver jewellery (no pearls) into the container and then cover the silver Jewellery with bi-carb. Pour boiling water over the top of the jewellery and you'll see the black "fizz" out. Then rinse with cold water and dry your silver with a silver cloth. For more info check out www.eurogoldjewellery.com.au.