It is obviously sensible to take a few precautions with your jewellery. When jewellery is worn next to the skin, it becomes clogged with oily debris mainly composed of dead skin, and dust and grit becomes lodged in this. Wearing rings while washing-up can also allow a greasy film to coat the backs of stones, and the inside of settings. So - do not wear your rings while washing-up or gardening or other similar activities. Also, while playing sports when you will perspire more than usual.
Diamonds are practically impossible to damage unless they rub against each other, but they will scratch other jewels in your drawer, particularly gold which is a very soft metal. Always keep your jewellery in a fabric lined box and not bundled together with other pieces which will scratch the precious metals.
The main purpose of cleaning jewellery is to remove all the greasy debris. Cleanliness affects a diamond's beauty. A clean diamond is more brilliant and fiery than the same diamond when it is dirty. Dirt or grease on the top of a diamond reduces its lustre, whilst dirt or grease on the bottom of the diamond interferes with the diamond's brilliance and sparkle.
Most gold jewellery and precious stones can be cleaned in warm soapy water, and should be gently brushed using an old tooth brush. Be sure to remove caked-on grease and other dirt from the backs of stones. Take care not to let diamonds rub together or scratch other jewels.
One important tip - always clean your jewellery in a bowl and never in a hand-basin or sink. If stones become loose in cleaning they can easily be lost down the drain!
High carat alloys such as 18 carat and above, will not usually become tarnished, and will not be harmed by household chemicals. Lower carat gold can be harmed by contact with chlorine based bleach and cleaning chemicals. The best way to avoid tarnish is to buy 18 carat gold jewellery, which hardly ever becomes tarnished
Silver tarnishes easily, but the tarnish can be simply removed using proprietary silver cleaning solutions, such as Goddard's Silver Dip.
Clean platinum with warm soapy water, as for high carat golds. Platinum, like high carat gold alloys is highly resistant to tarnishing.
Another important tip - always insure your jewellery and keep photographic records in case they should be lost or stolen.