Gold is a metal that does not rust, its composition is 75% pure gold and the remaining 25% may be of silver for green gold, copper for red gold, equal parts of silver and copper for yellow gold, nickel or palladium for white gold.

Over time the yellow and in particular in the red variants tend to grow darker because their alloy with copper triggers a little oxidation. White gold, on the other hand, does not have this problem, but the elimination through friction of the rhodium plating that is applied to even out the colour makes it lose its initial colour and shine with time.

The best way of cleaning any gold piece is simply to bring water to the boil, put in the pieces, remove from the heat, pour in ONE drop of ammonia and soap and leave to soak for about 10 minutes. Then brush with a very soft toothbrush to help remove any traces of grease and rinse with plenty of cold water. Dry with a linen or cotton cloth and finally, rub with a microfiber cloth designed specifically for jewels.