✦ Rhodium plated silver what is it ✦ Does it really exist ✦

Silver is a unique metal whose properties allow it to be used not only in the jewelry industry, but also in the manufacture of parts for technical devices, as well as in medicine. Silver is characterized by softness and ductility, which makes the metal susceptible to deformation, which is why it is not used in its pure form. To enhance the strength of the metal, copper is added to it. But even this does not protect silver from deformation, since the jewelry industry uses alloys in which the proportion of silver exceeds 90%. Therefore, to protect silver from the effects of negative factors, it is coated with a layer of rhodium. In the relevant literature and on electronic resources you can find such phrases as “radiated silver” and “rhodium-plated silver”.

Many people think that they are the same thing, but in fact they are not.

Radium - greetings from uranium mines

The chemical element, the metal radium, was discovered by the Curies. Irene Curie was the first to discover that the decay of uranium produces a new chemical element that is even more radioactive than uranium. For this discovery, the chemist received the Nobel Prize. There is catastrophically little radium in nature; in almost a hundred years since its discovery, scientists have been able to extract only 1.5 kg in the laboratory. this metal.

The cost of a gram of radium is about $100,000; it is a radioactive element and is prohibited for sale by the state; it is rarely used in technology because it produces strong radiation. Therefore, the difference between rhodium-plated and irradiated silver is colossal; the latter option does not exist at all in jewelry.

Radiant or rhodium plated?

Rhodium plated silver bracelet

So, it has already been said above that rhodium-plated silver is silver coated with rhodium. Many people make the mistake of calling rhodium plated silver radiated. The word "radiated" comes from the name of the chemical element radium.

This element is radioactive, therefore, it poses a danger to human health and cannot be used in jewelry.

Radium was discovered by the spouses Pierre and Marie Curie, and received the Nobel Prize for this. They found that there was less radioactivity in pure uranium than when the uranium was separated from uranium ore.

Radium turned out to be a very expensive metal. At the beginning of the twentieth century, the price of radium was as follows: 1 gram of radium cost 200 kilograms of gold.

Despite its radioactivity, radium was used. Radon baths have been used for a long time to treat diseases of the musculoskeletal system and nervous system.

Radium is used for short-term irradiation of malignant tumors in the body. In the 20th century, radium was used in instrument making: in aviation and marine instruments and in special watches with illuminated dials.

Glowing paints also contained radium.

There were no markings on devices containing radium, so a dosimeter had to be used. Radium is now being replaced by less radioactive isotopes (for example, tritium).

Therefore, radium has nothing to do with jewelry.

Most likely, this split is caused by a spelling error.

Because of this confusion, it has long been believed that rhodium-plated jewelry is hazardous to health. Now this opinion has no basis.

Rhodium and rhodium plating

Rhodium belongs to the precious metals of the platinum group; the cost of a gram of rhodium in 2021 is approx. 670 dollars per 1 gram. Rhodium occurs in nature in its pure form; in the earth’s crust its content is up to 1*10–7%. main deposits of rhodium Mexican gold mines.

Rhodium is obtained industrially by processing platinum. Rhodium is absolutely not susceptible to oxidation, but the metal itself also has a main drawback - fragility. Therefore, it is used mainly for spraying and creating protective coatings.

Rhodium production technology

Native platinum is placed in cauldrons, treated with aqua regia (a mixture of concentrated nitric and hydrochloric acids) and heated for 24 hours. Dissolved platinum is passed through a catalyst and a new chemical element is obtained - rhodium, which is resistant to acids and alkalis.

Why is it plated with rhodium?

Silver, as you know, although elegant, is a finicky metal. Due to external factors, silver begins to turn black over time, and jewelry no longer looks so aesthetically pleasing. To extend the life of their favorite silver items, jewelers have come up with a trick - covering the silver with a thin layer of rhodium. Due to its properties, rhodium protects the base material from environmental influences and retains the bright color and shine of the base material of the product for a long time.

Rhodium plating is most often applied to silver items, less often to gold items, and never to jewelry in the mass market segment, due to the high cost of the metal itself. The rhodium layer is usually applied no more than 25 microns (can vary from 0.1 to 25 microns). This is such a thin layer that it is absolutely not noticeable on the product. But even this coating is enough to protect a ring or bracelet from scratches and other mechanical damage.

Composition and properties

Rhodium is a fairly rare and hard metal. In 2021, only 21.4 tons of rhodium were mined, and annual production does not exceed 31 tons. This is very little, considering the fact that it is used in many areas and is in many ways superior to platinum in its properties.

Rhodium has higher chemical resistance than platinum, is not subject to corrosion and oxidation, and is resistant to electrical erosion. In addition, an alloy of rhodium and platinum is the most effective catalyst for the production of nitric acid. And at the moment there is not a single alternative to this in the whole world.

But for what properties rhodium is widely used in jewelry:

Solid and durable
Not susceptible to oxidation
Resistant to mechanical damage
Capable of reflecting up to 80% of visible rays
Has a beautiful cool shine
Safe and non-allergenic

This is an ideal material for plating silver. Over time, any silver will tarnish and blacken and will have to be cleaned (we told you how to do this at home here). Plating with rhodium helps to preserve the natural bright silver shine of jewelry longer, while also protecting it from scratches. With rhodium plating, silver rings do not require polishing or cleaning after a short time.

Strength

As already mentioned, rhodium is a durable metal. Rhodium plating gives silver items greater wear resistance and rigidity, helping to retain their original shape. This property of rhodium is especially important for silver rings, which become deformed over time.

Samples

Silver is rhodium-plated with pure metal without a ligature (otherwise technically impossible). The fineness of rhodium-plated silver is usually 925. Gold is plated with rhodium more often, since it is more expensive than silver, and the coating greatly increases the cost of the item. According to the law, rhodium-plated products are branded according to the samples of the materials from which they are made.

Occasionally, costume jewelry is also rhodium-plated, but not mass-market jewelry, but designer jewelry, especially if it is produced in a limited edition.

What is rhodium plated silver?

Silver (or gold) coated with a layer of rhodium is called rhodium plated. The coating thickness is approximately 25 microns, which is half the thickness of a human hair. In salons, rhodium plating is carried out mainly at the request of clients.

Since rhodium does not oxidize from exposure to sweat, plating often becomes the only way to enjoy wearing silver jewelry. This applies to those who are allergic to metal and cannot have skin contact with metal products.

Unique properties of silver. Causes of darkening of silver

The main reason for the appearance of black plaque is metal oxidation. This is a consequence of the interaction of the master alloy in the Ag alloy with substances from the environment. Indirect and direct reasons for changes in the color of jewelry:

hormonal changes;
playing sports;
interaction with chemicals included in detergents and cosmetics;
high humidity.

Silver is often used in the production of jewelry. Pure metal and an alloy based on it exhibits the following properties:

reflectivity - determines the possibility of reflecting electromagnetic radiation incident on the surface; for silver this ability is higher than for rhodium (95-97%);
softness: in this parameter, Ag is second only to gold; thanks to its softness, the scope of application of the metal has significantly expanded;
plasticity: silver is used to produce thin wire and sheets of minimal thickness - this is a unique property due to which products of different shapes and parameters are created;
density: 10.5 g/cm3, which may mean the metal is superior to iron and copper, but silver is inferior to gold and lead in this characteristic;
color change: over time, Ag acquires a more pronounced yellow tint, but most often the metal reacts with other substances in an oxygen-containing environment, turns black, this is a natural process, it can be stopped by eliminating the alloy from the composition, eliminating all negative factors affecting the product.

Silver coin - darkening

Advantages of rhodium plated silver

Rhodium has an attractive color similar to platinum; the noble metal does not turn black and enhances the beauty of the jewelry. But these are not all the advantages of rhodium-plated silver.

Protects silver from corrosion and blackness.
Increases the shine of jewelry.
Allows you to create an original exclusive design of a ring or chain.
The decoration is less deformed. Rhodium plated enhances the mechanical strength of products.

Silver coated with rhodium slightly changes color, becomes brighter and shiny, and the silver dullness disappears. The main advantage of rhodium plating is that the composition is completely hypoallergenic. Rhodium is safe for children and pets. The same cannot be said about the radioactive element radium...

Disadvantages of rhodium plated silver

If we talk about the disadvantages of the coating, the first thing worth noting is that rhodium plating wears off over time. Considering the cost of the metal, a gram of which is 10 times more expensive than gold, sputtering creates a very thin layer. A coating of 15-25 nm is very small; you will see the first abrasions within a few years. In areas where the layer has been worn away, the silver will begin to darken.

Price. Rhodium-plated silver is several times more expensive than regular silver; in most cases, jewelry is made to order.

If you want to sell rhodium-plated silver or find out the exact cost of the jewelry, to determine the price of the product you will need a jewelry expertise that will determine how much rhodium was used for plating. To do this, it is necessary to disturb the top layer; this can adversely affect the appearance of the jewelry.

Properties and functions of protective metal

When studying rhodium-plated silver, it becomes possible to learn more about it, for example, to understand what purposes a protective coating is applied for:

improvement of decorative qualities;
reduction in the consumption of gold, platinum, and other precious metals, since in part silver products can be used instead of them - more affordable, but no less attractive;
prevention of deformation of the main product, since silver is soft;
preservation of the properties of jewelry under the influence of other external factors.

The main feature of rhodium is its high hardness. With its help, a white coating is created, and the products do not lose this shade for a long period. Other characteristics of rhodium:

silver-gray color;
resistance to corrosive environments;
loss of properties upon contact with acids; otherwise, rhodium exhibits chemical stability.

Silver rhodium plating technology

Rhodium is used mainly to cover 925 sterling silver and 750 sterling gold; jewelry can also be rhodium plated, but such procedures are done only to order and only for design solutions, not for the mass market.

Rhodium plating occurs using the galvanic method. The product is placed in the rhodium solution and an electric current is applied. Under the influence of electricity, rhodium molecules adhere to the jewelry, which acts as a cathode, creating a thin layer of sputtering.

Application in the jewelry industry

Due to its many positive characteristics, rhodium is in demand in many industries, but in reality it can not be used in all. The main reason for searching for similar materials is the usual shortage of metal in nature. Demand for it significantly exceeds supply. It is impossible to replace rhodium in terms of characteristics in industries such as the manufacture of temperature sensors, measuring equipment, mirrors, nitric acid, and so on.

Rhodium in jewelry is used not only for coating finished jewelry made of other metals. It is mainly used in the artificial cultivation of certain precious gems as a component of a certain filter.

Rhodium plating of silver - types

Rhodium plating is used to give the product additional hardness. Silver jewelry gets rid of blackness and acquires shine and a noble color. Often jewelry is rhodium plated to decorate inserts made of precious and semi-precious stones. Jewelers use two types of rhodium plating.

Standard

With standard rhodium plating, jewelry acquires a silver color with a cool, bright shine. Due to its hardness, rhodium perfectly protects soft precious metals from minor damage and scratches, preventing wear. The product remains attractive for a long time and looks new.

Black

Black rhodium plating retains its protective properties but does not have a classic platinum, but a black tint. Thanks to this, the jewelry looks like an old antique. Rhodium plating can have shades from blue-black to light gray. More often than others, black rhodium plating on silver is used if the jewelry is inlaid with pearls.

For black rhodium plating, a rhodium composition of a modified chemical formula is used; the same composition is used for black rhodium plating of gold. A black (gray) rhodium oxide coating is formed on the surface of the jewelry.

Reviews

Anna Ivanova: I'm delighted, it just shines. I decided to plate an old ring, my mother’s, with rhodium in order to wear it longer. I paid 800 rubles for a thin ring, but in my opinion, it’s worth it.

Tatyana: And I love such jewelry, it’s especially nice that they shine like gold and cost almost like silver.

Ivan: We applied this coating to wedding rings and noticed that as it wears out, the yellow color of the gold appears. Looks like an amateur. But there really are no noticeable scratches.

Silver rhodium plating process

Rhodium delivery can be performed at home; the following operations will be required.

The decoration is carefully polished, and special machines are used in workshops.
Polishing. Sanding and polishing are necessary to give the product a smooth surface.
The metal is washed with chemicals to completely degrease the top layer.
The silver jewelry is placed in a galvanic bath.
Fill the product with a special solution containing rhodium.
Electric current is supplied to the cuvette. Under the influence of current, rhodium ions tend to the cathode, the role of which is played by the rhodium-plated product.
The process continues until the coating thickness reaches the required value. It is usually determined by eye.

How does coating affect the cost of metal?

Ag belongs to metals of a lower price category than platinum and gold. However, its prestige, appearance and properties increase after the use of rhodium. In addition, this precious metal is expensive, and therefore the presence of a small part of it on simple jewelry allows you to transfer silver jewelry to a higher price category.

Expensive collections of famous jewelry houses

Rhodium allows you to make jewelry “richer.” But this is only an appearance; under the coating there is still the same Ag, so in most cases the cost of products of this type does not increase too much. Rhodium-plated silver is even used by fashion houses that produce jewelry, including Tiffany, Christian Dior, Gucci. This material goes best with topaz, ruby, turquoise, and amethyst.

Tiffany earrings

What is the difference between rhodium plated silver and regular silver?

Rhodium is very similar to platinum and white gold, so even jewelers find it difficult to distinguish these coatings offhand. Rhodinated silver can be distinguished from ordinary silver by the following characteristics.

Pure silver does not shine in the sun and has a slightly grayish tint. Rhodium-plated jewelry shines brightly in the sun (rhodium has 80% reflectivity) and has a specific shine during the day.
Even color. Sterling or pure silver has a non-uniform color, rhodium is an absolutely uniform metal.
Absolutely smooth. Products made of pure silver are treated with a sulfur solution to form an oxide film on the surface that will protect the metal. Therefore, silver jewelry does not have a perfectly smooth surface.

Rhodium plated silver compares favorably with other types of processing. Therefore, leading fashion jewelry manufacturers, Tiffany & Co, Christian Dior and Gucci, produce large collections that include exclusively rhodium-plated silver items.

If you have the slightest doubt about the type of coating, contact an experienced specialist. Rhodium-plated silver costs much less than white gold or platinum, which is often used by unscrupulous jewelers.

Protective silver coating for wide applications: pros and cons

When worn, silver jewelry loses its attractiveness. The need to use precious metal to improve external qualities is due to the fact that this metal darkens. The reason is the introduction of copper into the alloy composition. The most common cause is the interaction of jewelry with human sweat containing sulfur. As a result, the products turn black.

Pros and cons of rhodium plated silver:

Advantages of rhodium plated silver:

attractiveness - products acquire a noble color: clean, cold, white;

resistance to mechanical damage;

safety for health, because the metal is hypoallergenic;

resistance to most chemical environments;

bright shine.

This material also has disadvantages:

coating is not resistant to abrasives;

Before carrying out repairs, rhodium-plated silver is cleaned of its coating, polished, and after all work is completed, a layer of metal must be reapplied;

With use, the protective layer becomes thinner.

Is it possible to rhodium plate silver at home?

Since the rhodium plating technology is not complicated, many people believe that it is easy to do at home. However, the rhodium galvanization process has a number of features that can become an obstacle to home processing. In addition, the cost of chemicals and tools will significantly exceed the cost of one product.

Therefore, it is advisable to do home rhodium plating when mass processing jewelry. Otherwise, it is more profitable and easier to contact a workshop. The cost of coating and work is on average 1,500 rubles. But if you have decided to do homework, then read on.

Buy a platinum anode. Its cost is very high; it can be replaced with a titanium anode with a platinum coating.
To prepare a working electrolyte, rhodium electrolyte costs from 10,000 rubles. for 10 ml.
Sand the surface of the product and degrease it.
Immerse in a bath, fill with electrolyte.
Pass a current of minimal power and strength through the bath.

This is a rough description of the process, we hope you will not try rhodium plating your own gold or silver jewelry. And if you do, you will find professional advice. We have talked about home birthing only to give an idea of the procedure.

Jeweler's comment

Molokanov N.M.

Jeweler, 26 years of experience in jewelry production.

Even if the rhodium plating wears off and darker silver shows through, the item does not need to be thrown away. The precious metal layer is easily restored. You just need to contact a specialist - a jewelry repair specialist. You can do all the work at home, but in this case there is no way to control the thickness of the layer: if the value of this parameter is significant, the precious metal will begin to peel off; when there is too little rhodium, silver will appear.

How to care for rhodium plated silver

Rhodium plating reliably protects silver from oxidation and minor scratches. But this does not mean that you can wear jewelry without taking it off. Rhodium plated silver also needs care and respect. The rules of care are simple and not difficult to follow.

Rhodium coating can be destroyed under the influence of aggressive abrasives, solvents, and varnishes.
Rhodium-plated jewelry is stored separately.
It is recommended to remove rings, bracelets and chains before fitness and swimming, and of course when taking a bath.

But even with proper care, rhodium-plated silver will darken over time, so be prepared for this. The problem is solved by going to a specialist who will clean the product and reapply the coating.

Antique silver beads

How long the rhodium plating will last depends on the type of jewelry; for rings it’s at least 3 years; chains will last the same amount of time. Earrings retain rhodium coating longer than others - up to 15 years.

Product care

Like any other coating, rhodium requires regular cleaning. When processing rhodium-plated jewelry, the following rules must be observed:

Choose your detergent carefully. There are cases when the coating was cleaned with too aggressive surfactants, after which the integrity of the rhodium layer was damaged.
The use of abrasive materials is prohibited. They can scratch the protective layer, resulting in loss of shine and attractiveness.
Silver care products cannot be used to clean rhodium plated items.
Chlorine and sweat negatively affect the coating. You should avoid visiting fitness centers and swimming pools with such decorations.
Choose a jewelry storage case carefully. It is forbidden to use a regular cardboard box for these purposes, since the sulfur contained in the cardboard will damage the protective layer.
Avoid contact with other jewelry. Do not put other rings on adjacent fingers.
Protect your jewelry from mechanical damage.

Compliance with these recommendations will allow you to keep the rhodium-plated product in order.

The service life of the coating depends on the type of decoration. For chains and bracelets it is six months. Rings can last 2-3 years. Earrings are worn the longest – up to 15 years.

Rhodium plating is very popular due to the positive qualities that the product is endowed with. Before purchasing jewelry, we advise you to inquire about the type of coating. This will allow you to calculate all maintenance costs associated with restoring the protective layer after natural wear and tear.

How to clean?

Cleaning rhodium-plated silver at home will not always be effective. Although it is quite difficult to scratch rhodium, it is still possible. Therefore, no abrasive cleaning agents should be used. The best option is a soap solution. It is suitable for cleaning any jewelry - with or without stones, with or without coating.

If you notice even minor damage or cracks on the surface, then without hesitation you need to take the jewelry to a specialist. The technician will carefully remove the damaged old layer and apply a new coating.

In general, jewelers recommend updating the rhodium-plated layer every 3-4 years (less often, it all depends on the intensity of wear).

How to clean it yourself

Although it is very difficult to scratch rhodium, this does not mean that it is impossible, but you will not be able to remove the scratch yourself. When polishing with abrasives, the entire composition will be removed, so jewelry should not be cleaned with abrasives or aggressive compounds.

If you find that your jewelry is scratched, there is only one way out - take it to the master. You can clean the product from dirt yourself with a soap solution. The product is carefully applied to the dye and rubbed with a soft cloth. The same cleaning method is used for all jewelry with and without stones.

Rhodium-plated silver jewelry can be combined with any precious or semi-precious stones. The exquisite design and beautiful colors of the jewelry will suit any toilet, the main thing is that the jewelry brings you joy.

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Tags:radiated silver, rhodium plated silver

Advantages and disadvantages

To the advantages of rhodium plating, you can add the ability to choose the color of the coating (black looks chic and modern in combination with precious stones) and even change the color of an old piece of jewelry by simply taking it to the workshop.

Reading about the positive qualities of rhodium-plated silver, it is difficult to imagine that someone might not like it. Let's be fair - in addition to resistance to damage and aristocratic radiance, there are negative aspects. I will dwell on them in more detail.

It is difficult to damage rhodium, but it is possible. If a scratch or crack appears on the surface, polishing will not do the job - you will need to completely remove the layer and reapply it. The same applies to damage to the material itself - for example, breakage of a ring.
Rhodium plating needs to be renewed every 3–6 years (depending on the intensity of use of the item).
If the jewelry is antique or antique-style, it will not be possible to protect it from damage with rhodium - it will begin to shine like new, and the rhodium may lie unevenly.
The coating significantly increases the cost of the finished product.

Gilding

A thin layer of gold plating is applied to the product. Basically, 750-carat gold is used for this technology. But there are exceptions when the manufacturer uses higher quality metal. Sputtering with precious metal does not affect the declared sample in any way.

The cost of silver items when gilded increases. With constant contact with an aggressive alkaline environment, the gold plating layer can quickly decrease. Therefore, it is recommended to take care of things that have such a coating (remove them before taking water procedures, do not swim with them in the pool). If you follow these simple recommendations, your gold-plated silver jewelry will look great and could easily become a family treasure.

Do you like stylish things inlaid with stones? If you are not indifferent to boxes, cigarette cases, brooches, then go to the online catalogs of our website - you can find a lot of interesting things for your collection in them.

Areas of application

Every year, huge amounts of rhodium reserves are consumed in various industries. It is one of the most sought after metals and is considered precious, but its use is limited only by the impossibility of using a cheaper alternative.

Every year, thousands of kilograms of rhodium are required to produce nitric acid. The metal base is a powerful catalyst. One cannot do without this chemical element in the production of laboratory glassware, containers and test tubes. This is explained by the fact that the substance does not interact with practically any compositions, which means that the flasks can be safely filled with any compositions.

Rhodium is also in demand in other areas of life:

allows you to measure high temperatures; sensors can record 1800 degrees Celsius without melting;
in car exhaust systems it is used as a catalyst;
used in the production of liquid crystal monitors.

During the year, a person mines and consumes approximately half a ton of rhodium, and the total reserve is estimated by geologists at 7-8 tons. They are trying to replace it using other metals, especially in the jewelry industry.

Blackening technique

Technologists call blackening the process of treatment with a special composition that includes sulphides of sulfur, silver and copper. Russian jewelers have been familiar with this technique since the 17th century. The craftsman applies a layer of powder to the decoration. Then it is sent for firing in a special oven. When the desired temperature is created, the niello melts and is absorbed into the surface of the base. This treatment is characterized by increased abrasion resistance.

Types of coating

Most often, rhodium plating is used to impart a noble, cool shine to white gold products, which, even with a high standard, still have a yellowish tint. No less popular for plating are platinum and silver jewelry, as well as some items related to costume jewelry. The cost of the latter, if there is a layer of rhodium, will fluctuate within 2 thousand rubles.

Today, thanks to special additives, rhodium plating can complement jewelry not only with a white shine, but also with a pinkish, yellowish or golden shine. There is also black rhodium.

In jewelry, it is used to give jewelry an aged appearance or to enhance the shine of certain gemstones. Very often, for additional strength, the place where the stones are attached is precisely this part of the jewelry that is coated with rhodium.