Rhodium plating: what it is and when it is useful for your jewellery
A bath of shine: this is how we could define it rhodium plating, the treatment used in jewelery for make white gold and silver jewels more brilliant. It is a procedure that is not only aesthetic, but also useful for protecting the surface of the jewels from external agents that could damage it. So let's see in detail what it is and how it works.
What is rhodium plating
The name comes from born, a precious metal, indeed the most precious in the world: his value, in fact, significantly exceeds that of gold. The reason is in the difficulty of finding and extracting: rhodium is very rare and is often found in minerals of other metals, such as platinum. It is silvery-white in color and very resistant, so much so that it is also used in industry. In jewelry it is often linked to platinum, to increase its hardness, and precisely as a treatment to increase the brightness of white gold and silver.
How rhodium plating works
La rhodium plating, therefore, is the process that allows the jewels to be covered with a thin layer of rhodium, the thickness of which can range from a minimum of 0,1 micrometre (1 micrometre, in the past called a micron, is a thousandth of a millimetre) to a maximum of 25 micrometres. The treatment takes place through electrolysis, the process that obtains a chemical transformation through electricity. Electrolysis was discovered by the Italian chemist Luigi Brugnatelli in 1805 and is also the basis of other metal coating processes, such as gold and silver plating.
The procedure involves a galvanic bath (in fact it is also called "galvanic rhodium plating"), i.e. a tank that contains an aqueous solution of the rhodium salt. The jewel to be rhodium-plated is immersed in the tub and covered with micro-particles of rhodium by means of electricity.
When is it useful to rhodium a jewel
There are several results that can be obtained from this treatment, which, as already mentioned, does not only concern the external appearance of the jewels, but also their care over time.
When should a jewel be rhodium-plated?
– When you have a jewel that shows the signs of time and wear and is dull and/or marked on the surface: the rhodium plating it will bring it "new", giving it shine and splendor.
– If you want greater protection and durability: the surface of the jewel, treated in this way, resists scratches and corrosion risks better and longer.
– In the case of nickel allergy: the rhodium plating protects the skin from contact with nickel, which is sometimes used for white gold and silver jewellery, and is well tolerated by allergy sufferers.
It should be emphasized that the layer of rhodium can also wear out over time, becoming thinner and therefore requiring new rhodium plating.
Among the possible disadvantages, we must mention the cost of the treatment, which can be high: the use of such a rare and precious metal is certainly not cheap, but the cost can be balanced by a greater durability of the jewel.
How to clean rhodium-plated jewelry
If the general rule for the jewelry care suggests avoiding chemical products and aggressive treatments, this is even more true in the case of rhodium-plated jewellery. The risk, in fact, is to damage the rhodium layer, thus nullifying the whole treatment.
The ideal cleaning is therefore that with only water and a very soft cloth or brush.
To protect it as long as possible rhodium plating, it is also advisable to avoid contact with other jewels, which could create scratches on the rhodium-plated surface.