Historical facts
Rhodium was discovered in 1803; it was obtained by studying platinum, which most often includes this metal. Rhodium acts as an auxiliary element, and it is considered the most expensive among natural metals.
In Russia, this element was not used for a long time; it was sold for next to nothing to Europe or was completely thrown into waste, considered useless.
We invite you to familiarize yourself with Ruby or Garnet: which mineral is more valuable and how to distinguish them
Only during Soviet times was an institute created to study the properties of noble metals. Scientists have finally managed to study rhodium and obtain information about its properties.
Rhodium belongs to the group of platinoids. Rhodium plating has the following properties:
- Not susceptible to aggressive acids and alkalis.
- Gives the product strength and durability.
It is worth noting that rhodium was not always used to give jewelry its shine and characteristic whiteness. Gold was mixed with nickel, and rhodium was added to the alloy, wanting to reduce the cost of production.
The experiments ended with a large number of people being harmed by the decorations. The reason is that nickel causes allergies. After an unsuccessful experiment, we remembered rhodium, which does not cause allergies and helps give gold its characteristic white color and shine. The use of this metal in the composition of the ligature led to the fact that the cost of jewelry increased sharply.
Rhodium was discovered by an unremarkable doctor: William Wollaston, this discovery made the scientist rich and famous. But in essence, he simply tried to dissolve the metal in acid.
Tips for choosing silver jewelry
In conclusion, I would like to share with you a few tips on how to choose silver jewelry and not run into a fake:
- Try. Always look for a sample on the product. Usually the hallmark is placed on the inner surface of the jewelry.
- Certificate of conformity. You will only need it if you choose a product with a gemstone. This will guarantee the authenticity and quality of the stone. Feel free to ask for a certificate from a consultant or seller in an online store.
- Color and shine. If they try to sell you ordinary silver under the guise of rhodium-plated silver, you will know right away. Look at the color of the metal. Natural silver has a slightly grayish tint and is not shiny, but rhodium-plated jewelry will be bright and shiny.
What is rhodium?
Rhodium is a noble metal from the platinum group. Outwardly, it looks like silver and has a cool, light silvery tint. Durable rhodium is resistant to corrosion, meaning it does not oxidize, does not darken over time, and is scratch resistant. However, at the same time, it is a very fragile metal; rings or earrings are not made from it: they would be too expensive and fragile, but they are used to coat other precious metals.
Rhodium price on the world market
Everyone knows that precious metals cannot be cheap. And since rhodium also belongs to this category, the price per gram of the metal, which is also quite rare, is also quite high.
Until November 2008, the price of rhodium rose inexorably, reaching a shocking critical level of $10,100 per troy ounce (about 31.5 grams), after which it collapsed to $900.
The graph shows the price of rhodium per troy ounce in US dollars over the past 10 years. As you can see, rhodium reached its maximum in 2008. This was rhodium’s finest hour: its price was 10 times higher than the price of gold. Since 2012, the price of the precious platinum group metal has stabilized somewhat.
The graph shows the price of rhodium per troy ounce in US dollars since May 2015.
Types of rhodium plating
Rhodium plating is used to achieve several purposes: the formation of a hard wear-resistant layer, the elimination of blackness in silver jewelry that occurs during the oxidation of silver, giving the product shine, and decorating inserts made of precious stones.
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.
Rhodium plating is used to achieve several purposes: the formation of a hard wear-resistant layer, the elimination of blackness in silver jewelry that occurs during the oxidation of silver, giving the product shine, and decorating inserts made of precious stones.
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, while maintaining its protective benefits, can give the decoration the noble blackness of an expensive antique item. The coating can range from pale gray to jet black. Such items inlaid with black pearls or black stones look amazing.
The effect is achieved by changing the chemical composition used in the rhodium plating of gold, as a result of which a layer of black rhodium oxide is formed on the surface of the product.
Rhodium plating technology
The process is carried out by electrolysis. Thoroughly cleaned jewelry is placed in special solutions and an electric current is passed through them. With this treatment, rhodium molecules are embedded in the top layer of another metal, forming a uniform, durable coating no more than 25 micrometers thick, which is 4 times thinner than a human hair.
White gold plating
When using rhodium to process white metal products, an additional layer is applied over the entire surface of the product. This is due to the fact that the base alloy matches the color of the protective coating. Even if the top layer is erased or damaged, the difference will not be noticeable. In some cases, when working with light precious metals, rhodium plating is used for protective purposes.
Processing of yellow and red gold
In this case, the craftsmen adhere to the same technology as when working with white gold. The main difference lies in the partial application of rhodium to the surface of the product. The fact is that over time, the base metal will gradually begin to appear through the additional layer. As a result, the appearance of the decoration will deteriorate and the aesthetics will be disrupted.
When working with non-ferrous precious metals, only the stock for the stones is coated with rhodium, increasing their reflective ability. After treatment, the brightness of the shine increases significantly.
Rhodium plating is very similar to the gold plating process. In both cases, a thin layer of metal is applied to the product, which changes the appearance of the product and acts as protection. The main difference is that the rhodium layer gives a white color, and the gold plating gives a yellow color.
Isn't this dangerous?
To ensure good adhesion and high-quality structure of the precious metal in the coating, it is important to carry out the correct chemical treatment of the surface. If necessary, gross defects are removed on a polishing machine.
If the sequence is not followed or one of the preparation stages is skipped, there is no guarantee of obtaining high-quality sediment. Removing low-quality coating is difficult, it requires additional time and entails additional costs.
Despite the many chemicals used in processing, coated products are completely safe to use. After rhodium plating, no traces of electrolyte remain on the surface of the parts.
Receiving technology
Rhodium is applied to metal objects by electroplating. The anode (electrode with a positive potential) is the auxiliary product, and the cathode (electrode with a negative potential) is the decoration. The result is a layer of rhodium with a thickness of 0.1 to 25 microns.
Before starting the process, the item must be thoroughly polished, otherwise the coating will visually highlight the damage present on the surface. The best option is to process the item immediately after purchase (if this was not done at the factory).
Main advantages and disadvantages
Rhodium-plated silver has many advantages over pure material. Thanks to this, jewelry becomes of higher quality and will delight owners with its appearance for a long time.
, several main ones should be highlighted
- Safety for humans. Rhodium does not have a negative effect on people and does not emit any toxic substances. In addition, it is harmless to children and pets.
- Durability. Silver jewelry with rhodium plating will last much longer than without it. At the same time, it will retain its properties for the entire period of operation.
- Inertia. Silver coated with rhodium practically does not come into chemical contact with alkalis, acids and other aggressive compounds.
- Beauty. Rhodium plating has an attractive silver color, making it suitable for creating fine jewelry.
Rhodium plating has not only advantages, but also disadvantages, which is why it is rarely used when creating exclusive and very expensive jewelry.
The negative aspects include the following:
- Gradual erasing of a thin layer. If a silver item is worn frequently, its owner will have to periodically renew the rhodium plating. The frequency of this procedure will depend on the thickness of the surface layer.
- Expensive. Rhodium is very expensive, so even the thinnest coating of this precious metal can only be afforded by a wealthy person.
- The need to destroy the integrity of the rhodium plating. To establish the exact cost of the jewelry, a special examination will be required, which involves scraping off grains of rhodium.
Pros and cons of rhodium plating
The obvious advantage is strengthening the surface layer of the metal, increasing service life due to increased resistance to scratches and damage. Many people find such jewelry more beautiful and sophisticated than jewelry made from conventional metals.
If you have a rhodium-plated piece of jewelry in front of you, then it is impossible to visually determine what gold or even what metal it is made of. I am inclined to classify this feature as a disadvantage.
Another negative side is that such coverage does not last forever. It wears off and may be damaged or scratched. If the procedure is performed poorly, the rhodium layer peels off from the surface of the product. And even a perfectly performed rhodium plating will require periodic repeat procedures, for which you will have to pay each time.
Difference from other metals
Rhodium plated silver is quite difficult to distinguish from other metals. The greatest external similarity of this material is observed with platinum and white gold. In order to accurately determine the type of coating, it is necessary to take into account the main characteristics. Among them the following stand out:
- Any other metal will be significantly inferior to rhodium-plated silver in terms of shine. If you need to determine the material of an unprocessed product, then you should look for the desired one by the gray or light black tint of the surface.
- To find differences from white gold, a visual inspection of the jewelry should be carried out. It will help determine the metal sample and the shape of the marks, which differ for each material.
- Rhodium-plated silver differs from platinum in the same ways as white gold.
If the buyer of jewelry is not a professional, then the work of determining the type of material should be entrusted to a highly qualified specialist. Based on experience, he will carry out the necessary manipulations and make his verdict. This option, although expensive, allows you to reduce the likelihood of error to a minimum.
To determine which rhodium plated silver is best, you need to understand the properties and characteristics of each. This is also a rather difficult task that only professionals can handle.
Gold rhodium plating
Rhodium plating, what is it? Gold is a very soft metal by nature. It wears off quickly, loses its original shine, and is easily scratched or damaged. Gold items are plated with rhodium to increase durability and make the jewelry more durable.
The process of applying a layer of rhodium to metal is the same as when coating silver, gold or costume jewelry. On red gold, rhodium is most often applied only to the places where the stones are attached or to the lock of the decoration. This gives strength to the most vulnerable places in the decoration. The sparkling white color of the coating will remain on the jewelry longer if you protect it from exposure to aggressive environments and mechanical damage. Despite its strength, the shelf life of rhodium plating is from 3 to 5 years.
What does rhodium plating mean for an entire red gold item? This coating increases the strength of the product. The color of rhodium depends on the impurities and does not necessarily impart a white shine to the plated item. However, completely covering a piece of red gold jewelry is not beneficial. After the white coating is erased, the red gold will lose its attractive appearance and the coating will need to be renewed. The price for such decoration will be lower than for its uncoated counterpart.
White gold rhodium plating
Rhodium plating on the entire product is most often used on white gold. Such a metal does not exist in nature. White gold is an alloy of platinum, nickel, gold, and silver. It has a yellow tint. The higher the metal standard, the yellower the product itself. Rhodium plating gives the jewelry a platinum white shine and a marketable appearance. Such products are readily purchased. A rhodium-plated white gold engagement ring will not lose its original shine for many years. With daily wear, friction, and exposure to the environment, rhodium coating will prevent the ring from deteriorating.
The rhodium-plated surface has a mirror-like shine and zero roughness. Light is perfectly refracted in such a product. This looks most advantageous on white gold jewelry.
Reviews
Maria: My husband gave me rhodium-plated earrings. I love them very much and wear them almost constantly. I am allergic to gold jewelry, but such jewelry does not cause any negative effects. True, it's time to update the spraying.
Svetlana: I bought myself a ring made of white rhodium-plated gold, but, unfortunately, not everyone is familiar with this method of processing products. Many people mistake this thing for jewelry, which I personally don’t like very much.
Olga: I received such a thing as a gift, but I wear it reluctantly. Although the metal is gold and really has a bright shine, its shine seems dead to me.
Silver rhodium plating
There is a category of people who do not wear gold in principle, but are satisfied only with silver items. Rhodium plating of this metal occurs in the same way as gold. It will be relevant for those people who want to protect silver from oxidation and darkening over time.
Rhodium plating of silver will help jewelry shine even more and look like a newly purchased item for many years to come. This result can be achieved because rhodium does not oxidize in water or air, and also does not react with acids.
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.
Differences between rhodium plated silver and regular silver
This metal has common external features with white gold and platinum. Rhodium plated silver differs from conventional products in a number of ways:
- Visual effect. Rhodium-plated silver is characterized by a specific shine and bright shine in the rays of light. Pure metal does not shine and has a tint of gray.
- Rhodinated silver differs from sterling or pure silver in its even color and special ductility due to the copper in its composition. The rate of its oxidation depends on the mass fraction of copper and the type of skin of the owner.
- Oxidized silver is pre-treated with a sulfur solution until a thin oxide film is obtained. The convex parts of the jewelry are polished, giving the effect of artificial aging. This is how it differs from rhodium-plated elements.
- Blackened silver contains some lead and sulfur. The alloy has an even color, but unlike rhodium-plated areas it does not shine.
As you can see, rhodium plated silver compares favorably with other types of processing. For this reason, even leading fashion jewelry manufacturers such as Tiffany & Co, Christian Dior and Gucci produce separate collections that exclusively include rhodium-plated silver items.
If you have the slightest doubt regarding the type of coating, we recommend contacting an experienced specialist. Rhodium-plated silver costs much less than gold or platinum, which is often used by unscrupulous jewelers.
Rhodium plating of jewelry price
The rich and attractive shine of rhodium-plated products cannot leave jewelry lovers indifferent. Even those who are allergic to metal can afford rhodium-plated rings, earrings and chains. The strength of such a coating will leave the product itself intact for many years. If the layer is damaged, it will not be difficult for the jeweler to apply it again to the jewelry. The price for rhodium plating of jewelry in jewelry workshops starts from 1000 rubles/piece.
Cost of the procedure
Much depends on the method the jeweler uses for manipulation. Rhodium plating is offered in almost all jewelry workshops, and the indicated prices and the formation of the cost itself vary greatly: in some shops the weight of the product is taken as a basis, in others - the coverage area.
On average, a ring or chain can be plated with rhodium for about 300 rubles. However, prices for updating or restoring such coverage are usually 3-4 times higher than the initial procedure.
Why isn't all jewelry rhodium-plated?
Of course, rhodium will protect your jewelry from external influences, but this coating is not always necessary, because it also has disadvantages:
- Price. The noble metal belongs to the platinum group, so its cost will be high. Sometimes it is simply unprofitable to rhodium plate jewelry, for example, if we are talking about a simple silver ring or chain.
- Complicated procedure. Not all workshops perform the rhodium plating procedure, because this requires expensive equipment and salts that are difficult to find.
- Fragility. After a few years, the rhodium layer wears off and you will need to look for a workshop where it can be renewed.
- Rhodium-plated jewelry cannot be soldered. If you need to resize your ring or resolder chain links, you'll have to say goodbye to the rhodium layer. It is washed off before interfering with the decoration, and then reapplied if the client wishes.
- Rhodium hides the natural properties of the metal. It is impossible to say whether this point is a disadvantage or an advantage. Many people like rhodium plating precisely because of its shine; some, on the contrary, prefer the natural shine of the precious metal.
Cautions
The properties of the metal have been studied for practical use. The effect on human health and other biological systems has been partially studied.
It was found that rhodium compounds are highly toxic carcinogens. However, the amount of metal in certified jewelry is safe for humans.
If an alloy of rhodium with cadmium (or zinc) is dissolved with hydrochloric acid, filtered, and dried, we obtain a powder. In fact, this is a mixture capable of detonating under normal conditions.
How to rhodium plated silver at home?
Anyone with at least basic knowledge of electrochemistry can carry out rhodium plating at home on their own.
Below are a few simple steps to carry out this procedure:
- Carry out preliminary procedures. You will need to sand and polish the surface of the piece to create a perfectly smooth surface for application.
- Rinse the jewelry thoroughly. This action is aimed at removing polishing residues and degreasing the surface of the product.
- Place the jewelry in a bath with a special solution. This is necessary so that the solution spreads evenly over the entire surface.
- Pass an electric current through the solution. It will provoke a chemical reaction, during which rhodium will be released. It will lie on the product in a thin layer and completely cover it.
A little about the solution. You will need a special solution for dipping rhodium plating of jewelry, which is concentrated rhodium sulfate. This substance is sold in specialized jewelry stores.
You need to heat the solution to 40-50 degrees and then pass an electric current through it. The recommended voltage between the anode and cathode is 3.5-4 V. Such products are sold ready for use.
The duration of this procedure and the current intensity depend on the desired result. This value is individual in each case.
In workshops, the rhodium plating procedure can cost up to 1000 rubles. It all depends on the company’s pricing policy and the current cost of rhodium.
After rhodium plating, the product will look brighter and cleaner than before the procedure.
Can the coating be removed?
After a certain period of time, the rhodium plating wears off . This is especially noticeable in those places where the product touches the human skin. The same applies to chains or bracelets, in which the links are constantly in contact with each other. As mentioned above, the wear life of such products depends entirely on the thickness of the rhodium plating layer. If the coating is made with high quality, even with daily use, the decoration can last a long time. For example, rings - about 5 years, earrings - about 10 years, bracelets and chains - about 4 years.
But even when it is partially or completely erased, it can be renewed in any jewelry workshop that is in the city. The cost of such a service will depend on the amount of coverage and how noticeable the changes are.
To slightly delay the moment of going to the jeweler, you need to know how to properly care for the purchased accessories.
- Such jewelry must be stored in a box, and separately from other items. It is very important that they do not come into contact with each other. A box with several compartments is best suited for storage.
- You should try to avoid any contact of jewelry with household chemicals. Therefore, it is best to remove them before starting cleaning.
- They also need to be removed before going to the gym, swimming pool or sauna. It is advisable to do this before bedtime.
- Rhodium-plated jewelry should not come into contact with skin care and decorative cosmetics. Therefore, before applying the cream to your hands, the ring must be removed. You can put it back on only when the cream has already been completely absorbed into the skin.
- Do not use products such as tooth powder or toothpaste to clean the product, as they can destroy the rhodium plating layer. To clean, simply rinse the jewelry in warm water and then wipe it with a special “jewelry” napkin. At the end, the product needs to be polished.
- Once every 5 years you need to go to a jewelry workshop to make sure the coating is intact. If necessary, the coating must be adjusted.
Jewelry using rhodium will appeal to everyone without exception. In addition, caring for them is as simple as caring for ordinary jewelry made of precious metals. The only drawback is that due to the rarity of this material, products with such a coating are quite expensive.
How to care for rhodium-plated jewelry
Here are a few simple tips that will help preserve the rhodium coating for as long as possible:
- Do not use abrasives or chlorine-containing detergents to clean products.
- Remove jewelry before working out in the gym or swimming in the pool. Sweat and water purification products negatively affect the protective layer.
- Do not store rhodium-plated items in cardboard boxes, as they contain sulfur, which can destroy the coating.
- Try to avoid contact of products with any other jewelry. Do not wear rhodium-treated or regular rings on adjacent fingers.
- Use running water and jewelry wipes to clean items.
Before purchasing the product, check with the seller how long it will take to contact the workshop to re-apply the protective layer.
What does rhodium plated silver go with?
In fact, rhodium plated silver jewelry looks good with any stone. Particularly noteworthy are, for example, topaz or sapphire, amethyst or alexandrite. Silver earrings with these stones shimmer very beautifully and look incomparable.
Sources:
- https://zolotoe-runo-sl.ru/splavy/rodij-v-yuvelirnyh-izdeliyah.html
- https://market.russam.ru/articles/o_juvelirnyh_izdelijah/p18765-chto_takoe_rodirovanie_i_pochemu_rodirovannye_ukrashenija_tak_populjarny/
- https://zhazhdazolota.ru/interesnoe/chto-takoe-rodirovanie
- https://vplate.ru/zoloto/vse-o-rodirovanii/
- https://VseoMetallah.ru/uvelir-isdelia/rodirovannoe-serebro-doma
- https://www.MosGold.ru/rodirovanie-yuvelirnyih-izdeliy/
- https://ProDragmetally.ru/dragotsennye-metally/rodij-v-ukrasheniyah.html
- https://socketmira.ru/dragocennye-kamni/radirovannoe-serebro.html
- https://vplate.ru/metally-i-splavy/vse-o-rodii-v-yuvelirnyh-izdeliyah/
- https://zoloto55.ru/sovety-yuvelira/vse-ob-ukrasheniyah-iz-rodirovannogo-serebra