Available ways to independently apply patina to coins after cleaning. Patination of coins (artificial aging) Patina on silver coins

Patination of coins is a quick and effective way to give them an antique appearance. There are many ways to apply a dark coating; you need to choose them depending on the type of metal and the desired shade. Most often, copper surfaces are subjected to the procedure, but sometimes coins made of nickel, bronze and even silver are aged.

The word "patina" is an Italian term. They first learned about it after a chemical experiment was carried out, the reaction of which was the transformation of the surface of the coin. On a silver or copper alloy, a dark coating looks beautiful, but on aluminum it is a cloudy film, which is why such items lose value.

An important condition for patina is complete coverage of the metal, because... individual spots will not add charm to the coin. Therefore, the uneven coating is removed and applied artificially. But, if the oxide film has penetrated deep into the alloy, it is not recommended to touch it. After cleaning, such products will turn into thin plates with shapeless potholes instead of a pattern.

Patination of coins is carried out for several reasons:

• The specimen was purchased or found in poor condition, with traces of corrosion and in need of cleaning. The appearance of excavated cash samples largely depends on the area in which it was found and the quality of the soil;
• increase in cost. Ancient coins with a noble brown coating are much more valuable than coins with green spots on the surface;
• ignorance of the true value of a coin with natural traces of oxidation and the desire to make it shine leads to the loss of the product’s significance. Most often, the patina is worn off or the coin is thrown into acid, after which its color turns yellow-orange.

Patination is carried out by a chemical reaction, during which a film or coating is formed. Many years of practice have shown what methods exist for applying patina and how to perform the procedure at home. In the process, you need to maintain the proportions of the substances, otherwise you may lose your rare coin forever.

Rules and methods of patination

It's no secret that metals oxidize over time when exposed to air and water. But this happens differently for different alloys. If steel or iron is destroyed as a result of such exposure, then the copper is covered with a dark protective film. It is this layer that gives a special chic to antique items, indicating their authenticity.

Often, in the desire to remove dirt from a coin, it is subjected to mechanical processing, as a result of which the patina is also removed. It is quite possible to return the noble insignia after this. Often, artificial patination of copper coins is justified from an aesthetic point of view, since it helps to hide the results of their cleaning.

Required Tools

Depending on the chosen method of applying patina, it is necessary to prepare tools and materials. The minimum set includes:

• glass or plastic container;
• selected chemical reagent;
• measuring cup;
• stir sticks;
• synthetic brush;
• degreasing liquid;
• rubber gloves;
• respirator;
• soap;
• sponge;
• unnecessary clean rags;
• cotton pads.

When all this is collected, you can begin the experiment.

Patina process

Of course, the presence of a “native” layer of oxides is much preferable, because it not only indicates the value of the specimen, but also reliably protects the coin from damage. If it is possible to preserve the natural plaque, then it is better not to touch it. When artificial aging is unavoidable, patina is applied independently. Patination is usually carried out using one of the following methods:

• dip coins into the prepared solution;
• place the monetary sample in a vapor-gas environment;
• apply the composition to the surface with a brush.

The quality of the final result directly depends on the method used to obtain the patina and how well the coin was prepared.

First of all, the coins are cleaned of fat and oxides. This is done with a cotton pad soaked in white spirit or gasoline. These liquids are good at removing greasy marks that interfere with the oxidation process and the reaction of the patination solution with copper. It is also necessary to wear gloves, because... the patina will lie unevenly on fingerprints left behind.

Features and methods of patination of coins at home

Depending on the metal, there are a fairly large number of methods for applying patina to a coin. All of them are feasible and do not require the knowledge of ancient alchemists and a special laboratory. Most types of patina can be achieved using simple methods, but you should not expect a super effect from it. The resulting layer will not hide coin defects, such as holes, potholes, nicks, smudges, but will only change their color.

The better the patination, the more valuable the coin will become. Experienced collectors know that artificial patina does not add financial value to items. But the patina, created according to all the rules, is no different from natural. The coin acquires a noble, rare appearance in the eyes of potential buyers. There is no universal oxidation method and the most suitable one can only be selected experimentally.

Patination of copper coins

Patination of a copper coin is performed with sulfuric acid. The product is applied to the metal, and literally within a few seconds it darkens. After the procedure, the product must be washed with soap so that oxidative processes do not continue. The patina resulting from sulfur ointment has a fairly rich black color, but it is unstable. If you rub the surface with a cloth, the plaque will be erased, so this method should be used as a last resort.

Patination of copper coins with ammonia is carried out in a well-ventilated area, because the vapors of the substance are quite corrosive. The coin being processed is oxidized in a closed jar or container. To do this, it is placed in a container with ammonia so that it comes into contact only with its vapors, and not with the liquid. Close the container tightly and wait 15-30 seconds. If you leave the coin for a long time, it can be damaged. The patina will not become darker, and pockets of corrosion will appear on the product.

Coping with the task of treating a coin with ammonia fumes is easier in words than in practice. It is either suspended or placed on a cotton pad inside the jar. This will allow it to develop a patina evenly on both sides. Alcohol is poured at the very end, after preparatory manipulations. Then close the container tightly with a lid.

Vapors of ammonia can cover a coin with an even layer of patina of a pleasant brown color in a few minutes. The shine is eliminated, and the product takes on a beautiful, rare look.

Patination of coins with potassium permanganate and copper sulfate gives quick results and a brown tint. They take unnecessary utensils for work, because... After patination, it is unlikely to wash off and will have to be thrown away. To prepare the solution, take 200 ml of distilled water and one gram of powders. Mix everything thoroughly, bring to a boil on the stove and drop a coin into the resulting mixture for 1-2 minutes.

The longer the coin sits in the solution, the darker the color of the patina it will develop. After 10 minutes the product will become almost black. This must be taken into account when achieving the desired shade of the oxide film.

Patination of silver coins

It is quite easy to darken silver coins. To do this you will need ammonia or ammonia. The product is placed in the freezer for 20-30 minutes. After this, they take it out, take it by one edge with tweezers and bring it to an open bottle of ammonia. It literally immediately begins to react to ammonia vapors and becomes covered with a gray patina. I stop the procedure when the silver acquires the desired shade.

There is another way to patina silver coins - with boiled eggs. They are boiled until stiff, cut in half and placed in a container with a fairly narrow neck. The coin is also sent there. The egg begins to release hydrogen sulfide, which causes the coin to become covered with a gray film. This method is good because it achieves the most uniform coverage.

The nuances of patination of coins in a natural way

You can apply patina to a coin without using the materials described above. There is a way to patina bronze naturally. To do this, the products are taken out into the sun and left there for quite a long time. For 1-2 years, you need to ensure that the coin is constantly exposed to sunlight. Of course, such a process can hardly be called fast, but its advantage is that the copper will acquire a naturally aged appearance. The “solar” patina will be difficult to distinguish from the natural layer of oxides.

At home, you can try to apply a dark coating with wood. Some types of wood produce tannins, which contribute to an “armchair-like” patina.

If there is no experience in patination of coins and even a clear understanding of how this process occurs, it is better to abandon the idea or let a specialist do it.

Over time, any coin becomes covered with a natural coating (thin oxide film), which is called patina. This occurs as a result of constant contact of the surface of the coin with the environment. This coating is like rust on iron. The only difference is that on coins made of copper, silver and other non-ferrous metals, unlike iron, the coating has a different chemical structure, and therefore an appearance, which can either increase the value of the coin several times or depreciate it. In any case, if the coin is old enough, the patina only indicates its authenticity, giving it uniqueness and special charm, most often increasing its value, except in cases of obvious destruction of the coin's surface and relief details.

Silver commemorative ruble of 1896 in honor of the coronation of Nicholas II in UNC state. During storage, it became covered with a natural orange-red patina, which significantly increases the price of the coin compared to a similar one, but without patina.

For a novice numismatist, a well-preserved coin, covered with a layer of oxide film, may seem damaged, faded; he would prefer to take the same one, but shiny, while a true connoisseur of art will choose exactly the one on which her many years of life experience have been imprinted in the form of patina .

Silver fifty-kopeck piece 1925 in UNC condition. Richly covered with iridescent iridescent patina. WITHThe cost of such a coin due to the multi-colored rainbow “pattern” can reach up to 20,000-30,000 rubles.

Silver fifty-kopeck piece from 1925 in UNC condition, similar to the previous one, but practically devoid of traces of patina. The cost of such a copy is about 1000 rubles, i.e. 20-30 times lower than the same, but in a beautiful patina.

If you wash off the patina with any cleaning agent, the old coin will look like new and will acquire an unnatural shine for its, say, 100 or 200 years, as a result of which its value will significantly decrease. In addition, after processing an old coin with a thick layer of patina, quite deep depressions - cavities - may remain in place of the oxide deposits, which can completely destroy the interest of experienced numismatists in this specimen.

A bronze coin of 3 kopecks from 1938 before cleaning is covered with a thick layer of oxide film and after cleaning, cavities are visible in those places where the deepest oxide deposits were located. This coin is not rare, but its example clearly shows what cleaning such oxidized specimens can lead to.

In addition to the very fact of the presence of patina, the most important thing is that its intensity corresponds to the year of issue of the coin. If you have a 10-year-old coin in front of you, completely covered with a spotted dirty green or even black coating, you should think about whether it is needed for your collection, and what it will look like in 30-40 years. Your best bet is probably to get a similar coin, but with little or no patina. It should be taken into account that a heavily oxidized coin can transmit its “disease” to other coins when stored together under certain conditions. It is precisely such specimens that can be subjected to any kind of gentle treatment, without the use of harsh chemicals and abrasives, without fear of losing its value and returning the coin to its original appearance, lost as a result of improper storage.

Silver jubilee coin of the USSR 10 rubles 1978 Proof, issued for the 1980 Olympics in Moscow. The reverse of the coin has an uneven layer of greenish mottled patina, probably as a result of improper storage. This patina can be washed off without fear of losing the value of the piece. How this can be done is described in a separate article.

You must understand that the line between a collectible coin covered with natural patina and a coin damaged by the external environment and subjected to corrosion is very thin. The difference is completely subjective, unless the coin is clearly damaged by chemicals, such as being in soil for a long time, or, conversely, there is an incredibly beautiful rainbow patina on an antique collectible coin that has been stored for decades in a special mahogany “cabinet.”

1911 US 1 Cent Copper Coin in N condition with a uniform greenish patina.

Silver commemorative ruble of 1898 in honor of the opening of the monument to Alexander II in UNC condition. During storage, this specimen became covered with a beautiful cabinet patina.

When purchasing a coin with an amazing patina, always keep in mind the possibility that it could have been formed not by the natural course of events, but by the skillful hands of the seller. There are many ways to achieve an artificial patina. It can be a deep chocolate shade on copper or a smooth matte surface on silver. Masters of working with coins, without straining too much, even apply a patina that sparkles with all the colors of the rainbow. And yet, despite the warnings, most numismatists admit that a coin with a beautiful patina looks much more attractive than an ordinary piece. Therefore, when purchasing a coin for your own collection, it is up to you to decide what percentage of the value of the purchased copy will be occupied by the patina, which is so pleasing to the eye.

Patina is a coating on the surface of a coin that is formed as a result of the reaction of the metal with the external environment. The patina on an antique coin emphasizes its ancient origins, makes the coin appear more natural, and most often increases its value. Regarding the increase in value, everything is not so simple here and each case must be considered separately. In some cases, patina, on the contrary, can significantly reduce the price of a coin. Of course, in this case we are talking about natural patina.

Patina is a natural process of oxidation of metal. This process is somewhat similar to the appearance of rust on iron. But there is a small nuance in this comparison. The natural patina on a coin can form over a long period of time, decades, often centuries. Such oxidation not only guarantees the coin's authenticity, but also prevents the metal from being completely destroyed by corrosion. In addition, the patina indicates that no mechanical actions were performed on the coin, it was not cleaned, the relief was not restored, and it was preserved in its original form.

In general, the color of a patina depends on many factors, including the thickness of the oxidation and the time at which the patina began to form. Coins made from the same metal can be coated with film in different ways. Also, the color and shade may depend on how often the coin was in unprotected hands, how it was minted, how it was stored, whether it had contact with salt water, whether it survived exposure to elevated temperatures (for example, a fire) and much more. There are several types of patina: loose or “wild”, iridescent, iridescent, “bullet”.

Patina color

Can vary greatly on copper coins. Black or dark brown is a reaction to copper oxide. The green and blue patina is caused by copper sulfides or sulfates. Powdery green or green-blue spots on a coin are the so-called “bronze disease”. In this case, the patina contains hydrochloric acid. This oxidation can, over time, completely destroy the flatness of the coin. In addition, the “bronze disease” can spread to other coins, so such specimens should be stored separately.

Ancient bronze coins may have a beautiful sandy or light brown patina. This coating appears due to grains of silicic acid salt contained in soil rich in sand or directly in the sand.

Nickel coins are subject to little patina. The color of the patina on nickel is light gray, sometimes light blue or even slightly golden.

There is also the term “cabinet patina”, which has become widespread mainly in Russia. “Cabinet” in pre-revolutionary Russia was a special wooden cabinet for storing coins. Vapors from wood and various varnishes provoked the formation of patina on collectibles.

Often, after cleaning, the coin looks very bad, I would even say not really bad. This is mainly due to the fact that the so-called patina was destroyed and the coin remained in a “negligee”. Selling such a coin is very problematic. It needs to be prepared a little for sale (like a car), i.e. apply patina.

In principle, patination of copper coins is not very difficult. The main difficulty is to ensure that the acquired color resembles the natural one as much as possible. There are many ways to patina copper coins, each with its own pros and cons. I only use three methods. I'll tell you a little about them.

Patination of copper coins using manganese and copper sulfate. Many numismatists consider this method the most “ideal”, since the color of the coin can be made from red to dark brown, and this induced patina will be very similar to the natural one. Patination occurs as follows: add 3-4 grams of manganese and about 10 grams of copper sulfate to water heated to 90 degrees (0.5 liters). Mix everything and place coins in this solution. As the solution cools, warm it up a little. Every 5 minutes, turn the coins over and check their color. Make sure the color turns bright brown. The big advantage of this patination is that the color is beautiful and relatively resistant to washing off.

Patination of copper coins using sulfur ointment. “Real” numismatists despise this method, which is quite simple. Take a coin and lightly spread sulfur ointment on it with your fingers. All this must be done in lukewarm water. Water is needed to make the coloring process slower. The final color of the coin will range from dark brown to matte black. The plus is that the worst coin can be revived a little, but the minus is that the color is unnatural and the patina is very easily washed off. In order to make the patina natural, after patination with sulfur ointment, the coin must be rubbed with a soft cloth dipped in oil. Sometimes you can achieve a very nice color.

I really like to patina copper coins naturally, i.e. sun and air. I conducted the following experiment - I placed the coins, cleaned to their very “nakedness,” on the roof of the house. Every two weeks I turned over the coins. The coins were burned by the sun and washed by rain for four months. The result was normal - the color changed from bright red to dull brown. If the coins had been left in the open air for at least 7-8 months, they would have become perfect. I highly recommend this method for those who are not in a hurry. The result will be amazing.

What is patina?

Oxidation is called rust. Oxidation of other metals - patina. They are fighting with the first one. They are chasing the second one.

They are persecuted not to drive them out, but on the contrary, to keep them. Collectors, for example, say that " patina on coins“This is the life experience of banknotes.”

The plaque testifies to the antiquity of the exhibit and the careful treatment of it by the previous owners.

However, in addition to the natural patina formed during the interaction of metal with the atmosphere and environment, there is also.

When purchasing other antiques, you should check the “authenticity” of the plaque.

Applying patina

Applying patina They are made artificially not only to deceive inexperienced treasure hunters and collectors.

The main purpose of man-made film is decorative. People are happy to purchase door handles, objects, vases and antique items.

There is no need to look for true ancient monuments and pay fabulous sums for them. You can simply buy an item with an unnatural patina.

It is created using various oxidizing agents. They are included in special mixtures.

Thus, the AK company produces a whole range of liquids and ointments for aging the creations of aircraft modeling circles and clubs.

By purchasing a standard set of parts for an airplane model in a store, for example, you can turn the construction set into a unique copy.

The company mentioned above offers compositions that form a patina on gray metals.

By the way, the so-called is also “the work of patina.” It comes in different colors.

Patina on metal

On some metals there is a film, on others it is red, on others it is red. The tone of the plaque also depends on the conditions in which the item was stored and used.

Those standing on city streets have a greenish patina. But, there are metallic ones with a touch of other colors.

These are already artificially obtained specimens. Let’s use an example to explain how you can dress the same metal in different “clothes.”

Black appears on the metal after it is lowered into the liver. This is a mixture of caustic and.

For obtaining artificial patina its thick mass is diluted in water. The solution is heated to 70 degrees Celsius.

Sometimes, the product is not completely included in the composition. This is done if you only need to blacken certain areas or decorative items.

Oddly enough, there are also old ones with an unnatural touch. The art of recreating patina was mastered in ancient times.

Pliny the Elder testified to this. A writer who arrived in Egypt from Rome recorded: “They don’t mint here, but paint.

Dust and sulfur are mixed with it. with additives are melted in a tightly closed vessel made of ".

They learned to paint greenish-gray only in the 20th century. Then they mixed iodide, water and .

The metal was dipped into the solution and it was covered with a noble film. It is nothing more than iodide.

When exposed to light, the plaque is partially destroyed. In some places, a clean base is visible from under the green “haze.”

You won't see the golden or brown patina. Either this is not possible, or the necessary reagent has not yet been invented.

Only copper, bronze, etc. can be coated with a brownish coating. The dark shade of “wenga” gives a solution of the same sulfur liver.

Paints are achieved using copper sulfate. The reaction requires a mixture of the substance with water and potassium permanganate.

The metal is kept in the mixture for 4.5 minutes. The experiment will not succeed if you do not pre-treat the surface. It should be low-fat and dry.

Man-made patina is impressive, but does not always protect the item. There is no film and metal base at the border.

This is a layer that prevents further spread of corrosion. It is he who slows down the process of destruction of ancient gizmos.

For example, it would take about a hundred thousand years for a coin to turn into sand. Without cuprite, the metal would turn to dust much faster.

The features of the middle layer between products and the film covering them were discovered in the USSR.

The repatination method was widely used in the Union State. The historical plaque was removed and replaced with an artificial one.

The latter was more aesthetically pleasing. But, after processing, some values ​​began to quickly collapse.

Scientists grabbed their heads, and they came up with the causes of the disaster. While studying the composition of natural patina, physicists and chemists discovered cuprite and its metal-saving properties.