Diamonds need caring to keep them looking at their brilliant best. They should be cleaned at least once a month to keep away the "dullness" that can be caused by skin oils, soap, cosmetics and even cooking grease. The only substance that does not stick to a diamond is water. A clean diamond will reflect better light.

There are several ways of keeping diamond jewellery clean.

The detergent bath is performed with a small bowl of warm suds using any mild liquid detergent. Immerse jewellery pieces in the suds and brush gently with a tooth brush. Rinse under warm running water and pat dry with a soft, lint-free cloth.

The quick dip method uses one of the liquid jewellery care products available. Follow the instructions on the kit.

The latest jewellery-cleaning device is the sonic jewellery cleaner. It is electronically operated and comes with its own solution and directions.

Some extra helpful hints to keep diamond jewellery looking at its best.

• It is better not to wear diamond jewellery when doing rough work or the dishes. Despite the durability of a diamond, it can be chipped by a hard blow along its grain.

• Take care when doing the housework, not to let diamond jewellery come into contact with chlorine bleach, as it won't harm the diamond but can pit or discolour the mounting.

• When placing diamond jewellery in a jewellery case, be sure to wrap them individually as they can easily scratch each other as well as other gem jewellery. Be sure to take all types of precious mounted jewellery to a jeweller at least once a year to check for loose settings and signs of wear.