Any type of jewellery, gold, silver, diamonds, gemstones or alloys, tends to worn next to the skin and will therefore become covered with oily debris formed by dead skin cells. Dust and grit them becomes clogged into this. Also if you wear a ring when doing the washing up and do not wear rubber gloves, a greasy film will coat the backs of any stones and the inside of settings.

Most gold jewellery can be cleaned in warm, soapy water and gently brushed using an old toothbrush. Eighteen carat gold and above does not usually become tarnished and is not harmed by household chemicals. Lower carat gold is easily damaged by chlorine based bleach and cleaning products, which can cause stress corrosion cracking.

Platinum can be cleaned in the same way as the high carat golds. The patina that develops over a period of time can be removed by a professional jeweller who will repolish it back to its original high gloss look.

Silver tarnishes easily and the only effective way to clean it is by using proprietary silver cleaning solutions such as a silver dip.

Jewellery manufacturers use ultrasonic cleaning tanks which are a mixture of ammonia and detergent with the ultrasonics providing agitation to speed up the cleaning process. Many jewellery stores now sell small ultrasonic domestic cleaners, but experience has shown they are on a par with the warm, soapy water method and no more effective.

It is very difficult to damage diamonds because of their hardness, but take great care that two do not rub together as they can scratch and cause abrasion to each other. Caked on grease and other dirt on the backs of the stones should be removed with warm soapy water and an old toothbrush, rinsed and dried with a lint free cloth. Also make sure that your diamond jewellery is stored in a jewellery case and individually wrapped.

Gemstones should be treated in the same way as diamonds. But take care when cleaning any sort of stone set jewellery that you do not do this in a washbasin or sink as if any stones loosen they will go straight down the drain.

Gary Ingram runs The Diamond Store.co.uk. An online store that provides advice on keeping and owning all kinds of Diamond Jewellery. From specialist Engagement Rings through to advice on how to avoid blood and conflict diamonds