Silver jewellery in particular will blacken over time, as it reacts with sulphur in the air, and even gold will benefit from a little care from time to time to revive it. This change on the surface of the metal is known as tarnish. Some people also find that their particular skin chemistry causes silver to tarnish more quickly than others. When tarnish does build up, I recommend these excellent cleaning methods:
Silver foam is my first choice for cleaning tarnished silver and gold jewellery. It is gentle on the metal, making it suitable for polished, textured and brushed finishes. Follow the directions on the pot, and wash well afterwards in warm soapy water. Thoroughly dry the piece after cleaning with silver foam to prevent watermarks forming.
Polishing cloths remove light tarnish with ease, and are ideal for very quick cleaning. A polishing cloth is a soft cloth impregnated with fine polishing compound, used directly on the jewellery. I recommend getting one to keep in your jewellery box and use it regularly to keep your jewellery looking bright. Polishing cloths are not suitable for brushed finishes, as the polishing compounds brighten the metal surface, giving it a brighter finish.
Liquid silver polish is excellent for cleaning heavily tarnished items with a polished finish. Liquid polish will also remove light scratches. Rub on with a cotton cloth and then buff with a clean soft cloth. Wash well afterwards in warm soapy water. Thoroughly dry the piece after cleaning with liquid polish to prevent watermarks forming. Liquid polish is not suitable for brushed finishes, as the polishing compounds brighten the metal surface, giving it a brighter finish.
Silver dip quickly brightens silver jewellery, but I find it often tarnishes again more quickly afterwards. Follow the directions on the pot, and wash well afterwards in warm soapy water. Thoroughly dry the piece after cleaning in the silver dip to prevent watermarks forming.
Washing up liquid - For intricate stone set items, for example claw set precious stone rings, cleaning the item in hot boiling hot water with a few drops of original washing up liquid added (I find ‘Fairy Liquid’ works very well) and then brushing with a soft brush (an old toothbrush is ideal) will remove any build up of dirt from behind the gemstones and instantly make the gemstones sparkle again.
This British company stock an extensive range of quality jewellery cleaning items and the website also is an excellent resource for jewellery cleaning and storage tips.