Silver - noble white metalIt's a metal from which a huge amount of jewelry is made on a daily basis. Fashionable jewelry brands are always happy to work with silver because the shiny texture of the metal is very presentable and also demanded by connoisseurs. Unfortunately, a number of factors can cause silver to turn yellow. The answer to the question why silver turns yellow contains a wide variety of causes, but yellowing can be prevented by knowing the prerequisites and getting rid of it with effective methods if necessary.
Silver: properties and applications of pure metal. Can silver turn yellow?
It has all the properties demanded by medicine. The finest devices are made of silver: for example, the 90% of the first generation of respiratory probes are made of it. If we exclude the aesthetic side applications in the jewelry industry, then you can describe the demand for it in the radio electronics: silver is used to make contacts, wire terminals, transmitter relays and other intricate spare parts, parts.
Important: In its pure form, argentum exists only in space, where it is not subject to oxidation by oxygen. The pure metal in its pristine form does not turn yellow because it is inert. But if the surface of silver has a microscopic layer of patina, it will begin to turn yellow when it interacts with a number of elements.
Yellowed silver: Causes
Yellowing is caused by a number of characteristic causes, which are justified by interactions with various chemicals. First of all, the influence of sulfur oxides leads to yellowing, second the reason can be direct oxidation by various strong substances found in the food industry as well as heavy industry.
Airborne sulfur emissions
In addition to the usual water vapor, nitrogen, oxygen, air always contains impurities. Their amount may be more or less - it depends on the environment of a particular area. For example, in the Southern and Northern Urals, the atmosphere is polluted with impurities of manganese, surica, various resins, and sulfur.
It is the prolonged interaction with sulfur that leads to the yellowing of silver - the formation of a thin film of sulfurous oxide.
Of rubberized items
What can be called rubberized objects? For example, polymer sleeves, gloves. Sulfur can be released from them in two ways waysbut the sulfur released from the polymer will always affect the metal. If silver jewelry worn on the hand and constantly touching the rubberized fabric, sooner or later it will turn yellow.
The ions will begin to interact with the sulfur and form a stable film in the form of an oxide-polymer compound. The second way to release sulfur is to expose the rubberized fabric to temperature.
If, for example, a rubber glove were to be incinerated, the atmosphere would "get" various toxic substances, including sulfur
From wrapping paper, clothing
Clothing, also packaging paper contains one substance, which consists of cellulose treated with sulfur. Sulfur tends to vaporize actively in the air, as well as when it interacts with water. Cellulose with sulfur leads to the formation of oxides on any metal, so paper industry workers are not recommended to wear jewelry at work, and after the shift all workers are necessarily cleaned: washed under the shower.
Reaction with oxidizing agents in the food industry
Oxidizing agents in the food industry are special persistent substances that are used to treat raw materials for food preparation. For example, margarine is a stream of steam treated with hydrogen derived from sulfuric acid. For workers in the food industry who have contact with acids and acid-containing media, such as lemon juice or citric acid, there remains a risk of yellowing of personal jewelry.
Drugs with bromine, iodine
Yellowing due to bromine and iodinated medications is the most interesting case. Exposure to silver can be direct and indirect. The direct one occurs when the skin at the place where the jewelry is worn is treated with iodoform solution. The surface of the silver will interact - it will be covered by a thin layer of iodine. This implies yellowing or acquiring a light brown hue.
Cosmetics and household chemicals
Washing a bath or plate with silver jewelry on your hand is possible, but not recommended because of the high alkaline content of detergents. Alkalis are milder substances, but when reacting with metals, they form basic or double-base bonds containing oxygen (the so-called HO (hydrogen+oxygen) residue). This leads to a light yellow plaque, which is not homogeneous in its composition. The same applies to cosmetics - creams, lotions.
Important: You can't buy waterless creams or lotions because atomic water is the basis of their composition. But you should look for products with micellar water, it contains attenuated hydrogen with a single-valent bond.
Sulfur compounds in sediments and water
It is not uncommon to see puddles with yellow edges after a rainstorm. such puddles are often found in cities with active chemical production and a powerful industrial sector, where "smoky pipes" are emitted. In particular, engine oil plants burn off "waste oil," releasing all sorts of compounds into the atmosphere: polymerized hydrides, nitrates and sulfur. Airborne sulfur compounds are condensed in clouds and rained out. In addition, emissions from factories can enter the water intake of a particular city.
People get caught in the rain or regularly use tap water without removing their silver jewelry. As a result, the jewelry begins to take on a yellow grayish hue.
Important: Pay extra attention to the water you use on a daily basis. Drinking water contaminated by emissions can not only cause your jewelry to darken, but can also lead to serious illness.
Industrial emissions into the atmosphere
Industrial emissions are not only related to the condensation of vapor in clouds. The atmosphere is capable of forming "airborne" chemical compounds that are constantly present in the atmosphere. A striking example is the factories of Nizhny and Verkhny Tagil or the industrial sector of Chelyabinsk.
Every day during metal smelting, airborne aromatic sulfur compounds are released into the atmosphere. They are weighted with metallic oxides and therefore cannot rise into the upper atmosphere, remaining in the "breathing space" of people. Such compounds lead to the yellowing of silver, the darkening of gold, and the appearance of a corrosive patina on other metals.
Probability of forgery
If tin or other metals similar in texture, but not precious, are added to the argentum, oxides are to be expected. The yellowing of silver is the first indication that there are many more accompanying metals than silver in the jewelry.
Important! Until the beginning of the 20th century it was not technically possible to refine silver. Until that time, it was extracted from the mines where tin was originally mined, so all silver after extraction to the surface already in the first year had a slight yellow tint. It was refined using artisanal methods.
The state of the human body
The claim that silver jewelry is an indicator of a person's health is not without foundation. It has been noted that jewelry turns yellow if it is worn by a person with tuberculosis or other lung diseases.
How to prevent the yellowing of silver
There are very effective, and most importantly, time-tested methods that will help qualitatively clean this metal from the yellow patina. The methods are simple and available to every owner of jewelry.
Separate storage
It is recommended to store each piece of jewelry separately, without allowing them to come into contact with each other. For this purpose, it is better to use special plastic bags "zip-locks". It is not that the jewelry affects each other directly. What matters is the texture of the silver. If you put silver ring to the earrings, a static charge will begin to form between them. In the air environment, the static charge will begin the micro-galvanic process of releasing impurities from the atmosphere. The result will be the appearance of a small yellow spot where the items are touching.
Dry and dark.
If you move your jewelry away from the open air and sun, you can protect it from all the possible causes of yellowing. This rule applies to all types of jewelry.
Prevention
As a preventive measure, you should occasionally dip your silver jewelry in a weak solution of hydrogen peroxide or vinegar. This will help get rid of the patina. It is especially useful if it is a necklace. Vinegar can bring it back to its former luster.
Take it off before sports
In order to prevent the jewelry from interacting with sweat when exercising, it is better to remove the jewelry. The interaction mechanism involves a complex chemical process that results in yellowing. Why is it yellowing Is the silver on your finger when you play sports? Because it is under the ring that sweat collects the most, it can cause irritations, "sweating", fungus. That's if the finger, but it can also be a foot, an arm, - the whole body.
Wrap in storage
In order to keep the atmospheric air from getting to the jewelry or to reduce its amount, it is recommended to wrap the jewelry in any material, such as flannel flaps, similar products. This is an old "grandma's way" of keeping silver jewelry presentable.
What to do with already yellowed silver: Top 5 cleaning products
Undoubtedly, the best treatment is prevention. But what to do if the silver has already changed color, losing its former luxurious appearance. You can find cleaning tools at the jewelry salon or in your kitchen.
Rinse in a soapy solution
How do you remove acid from anything? That's right, lye! Soap is the most readily available lye. If you make a soapy solution, and then put the jewelry, let it "sour," then lightly scrub with a brush, you can get rid of a weak plaque.
Important: The method does not work if the yellowing appeared several years ago and steadily adorns the jewelry.
Soda and foil
For the method it is necessary to prepare a sheet of foil, pour the baking soda, moisten it to form a baking soda pulp. Wrap the ornament in the foil so that it interacts with the baking soda. Then small pieces of foil are used to "wipe off" the jewelry from the residual plaque.
Brush with toothpaste
Toothpaste effectively removes plaque from tooth enamel. This property can also be used for silver, as the paste is based on substances with an alkaline component. The paste should be applied to the jewelry, leave it for a few hours, and then with strong movements clean it with a brush.
Soak in ammonia solution
Liquid ammonia is found in ammonia alcohol. It is a strong solvent not only for organic compounds, but also for metals. For silver purification from yellow plaque, put the piece in a container with ammonia and leave it for a few days. The ammonia will dissolve the patina, and the jewelry will become clean.
GOI paste
GOI paste is an abrasive compound, very thick in mass, but much softer than abrasive stone. The method is suitable for large jewelry such as bracelets, brooches, large earrings, etc. The cleaning is done mechanically, i.e. a piece of paste is used to grind the dirty surface.
A few unusual ways to clean
Unusual cleaning methods two methods that are available to professionals or residents of certain regions can be considered.
The first way is to make the ornament an anode (a negatively charged electrode) and place it in the electrolysis solution. Apply a light 12V voltage through the cathode, which is shorted to the anode. The voltage will electrify the anode and cause the yellow oxides to "peel off" and dissolve into the electrolyte.
The second method is ozonation. It is available to owners of jewelry who live in a mountainous area. After any thunderstorm or heavy rains, the air is saturated with ozone. For preventive cleaning, it is enough to take all the jewelry out into the air, which is saturated with ozone.
There is one more way which should be able to clean the silver. If it is a chain or a bracelet, you should wrap a white egg with it, then put it on the windowsill all night long. By morning, the jewelry should be new.
Cleaning silver with stones
For cleaning jewelry encrusted with stones, fits all methodsThis is because neither acids nor alkalis can darken gems. But if the jewelry is inlaid with cubic zirconia or other "ceramic fakes"It is recommended to cover the stones with a thin layer of polymer, such as liquid silicone, before cleaning.
Question and answer section
Why has the silver cross turned yellow?
Why is the silver yellowed after cleaning?
What should I do if my silver is yellowed?
Folk superstition about yellow silver
An old belief, which was widespread in the territory from the Volga region to Siberia, says that silver turns yellow on the body of a person on whom a spell or evil eye was put. Besides, if a silver ring turned yellow, it was an indication that the owner had serious illnesses of various kinds.
Especially actively promoted "witchcraft omens" if the silver first turned yellow, and then began to blacken.
Video: Why Silver Turns Yellow: Several Versions
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