Alloy of silver and copper in the compositions of the 8 main tests: properties and applications of various alloys from perfect sterling to elegant shibuichi

Сsilver is in demand in many fields, from investments to the space industry. The metal is more accessible than gold, but it has never been less popular. Silver was favored by royalty and was the currency of international trade.

In most cases, silver is alloyed with copper to improve the consumer properties and quality of such an alloy.

Features of pure silver and the value of the metal

Pure silver is a malleable and ductile element that belongs to the group of precious metalswhich already includes gold, platinum, and five other platinum-grade metals.

All noble elements share the unique property that they do not react to water, oxygen in the air, and other factors that can lead to corrosion and oxidation.

In its pure form, lunar metal is heavy; it is slightly lighter than lead, but heavier than copper. It has the highest electrical conductivity of all existing metals. It can only be dissolved in nitric, concentrated sulfuric, and hydrochloric acids.

The precious metal is used for minting coins, coating the contacts of electronic devices, as a food additive, in the manufacture of mirrors, and as a disinfectant. The fields of application are constantly expanding.

Silver alloy
Silver bars

The jewelry industry accounts for about 20% of global silver production. In this industry, various impurities are added to the pure precious metal to improve its wear resistance.

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The value of silver as a jewelry material is as follows:

  • It has excellent casting qualities and lends itself to all machining techniques;
  • Combines harmoniously with precious minerals;
  • Able to neutralize bacteria, harmful to humans;
  • Low cost;
  • Has a universal shade to match any color;

Silver is a valuable asset. Its current value in 2021 is about 70 rubles per gram. If we analyze the data of the Central Bank of Russia exchange, we can conclude that the price of the metal is increasing from year to year.

The healing qualities of the precious metal have been known since the dawn of civilization. It is able to have a beneficial effect on the cardiovascular system, intestines, to relieve headaches, nervous tension.

The positive influence of the moon metal on the human body was first described by Hippocrates, the progenitor of modern medicine. He used the precious metal to disinfect wounds, ulcers, and burns.

Important: Despite its beneficial effects, silver tends to accumulate in the body and cause poisoning. The presence of pure precious metal in drinking water can be very dangerous.

The perfect union of silver and copper

Ligatures are various impurities used to make the precious metal harder. The main alloying agent for silver is copper. Copper makes the precious metal stronger while maintaining its malleability and beauty.

The purity of the alloy is reflected in its value. The purer the material, the more expensive it is.

The perfect union of silver and copper
Copper and silver

The ideal combination of metals is called sterling alloy. It contains 92.5% of pure silver with the remainder in copper. This alloy is one of the most expensive and sought-after.

This union of copper and silver is ideal for creating jewelry: necklaces, chains, pendants, rings, earrings. It is used to cast a variety of kitchen utensils, souvenirs, and decorative items.

Other metals for silver alloying

Aluminum, cadmium, zinc, nickel, rhodium, and lead can be impurities. In addition to imparting hardness, the metals increase gloss and change the final color.

How a ligature is introduced into an alloy

When introducing a ligature, the precious metal is melted first. Copper is introduced in portions so that the alloy does not solidify.

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If several metals are fused, a more complicated technology is used. Let's look at the example of melting silver with copper, zinc, and cadmium.

First, each material is rolled into thin plates. The resulting plates are wrapped in silver sheets, bagged, compressed, and lightened. Then the discolored mass is melted.

The amount of ligature introduced is always strictly fixed. Even small deviations can lead to a deterioration of the entire alloy. For example, 1% of nickel will increase strength and 2.5% will make the alloy brittle. If more than 8.9% of tin is added to the copper-silver alloy, the material will become unstable and begin to react chemically with oxygen.

Assaying of silver from 600 to 999. Assaying according to GOST

A unified standard for the quality of silver is set by GOST 6836-80.

In the Russian Federation there are the following silver assays - 800, 8Z0, 875, 925, 960, 999.

GOST prescribes the fields of application of silver alloys. They are ranked by purity, for industry alloys of any composition are suitable. In the jewelry industry materials containing more than 72% of the precious metal are used.

Natural Silver Minerals
Silver Stones

Branding on silver in Russia and abroad

All precious objects produced for sale must be specially branded. The hallmarking is carried out by the Assay Office. The presence of the stamp is proof that the jewelry meets the requirements of GOST.

The stamp has the following structure: first comes the code of the assay office, then the mark of the assay certificate, and after that - the numerical designation samples.

The key feature of silver marking is that all information about the precious alloy must be inscribed in a figure resembling a barrel.

The marking can be placed in different places, as a rule it is hidden from sight:

  • On chains and bracelets - next to the clasp;
  • On the rings - on the inner rim;
  • On spoons - on the back of the handle;
  • The earrings have a clasp;

Table: properties of silver standard samples according to GOSTU

Alloy classDensity gsm3Melting point, CоBrinell hardness, kgf/mm2Tensile strength, kgf/mm2  Relative elongation
Pure precious metal10,З9960351849%
92510,29910-81068З029%
90010,З0890-77976З026%
87510,16810-77976З0ZZ%
80010,1З820-77979З1Z0%
71510,0079992ZZ27%
6259,85820-77990З1Z1%
5009,7805-7798529Z6%

The use of different types of silver

The field of application depends largely on the purity of the entire alloy. It is the assay that indicates the percentage of silver in the entire piece.

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Consider the most popular samples in ascending order of purity:

720

Because of its high copper content, the alloy has a yellow cast. It is practically not used in jewelry; more often it is used for needles, springs, clasps and other parts that are subject to heavy loads.

Sterling silver brooch
Raspberry Needle Brooch

720 proof retains its original appearance for a long time, does not succumb to deformation.

800 и 830

These two samples are extremely durable, and they are used to make a variety of decorations and cutlery. Kitchen appliances need regular care; without periodic cleaning, they can become discolored.

Samples were especially common in Turkey, Egypt, France, and Italy.

875

875 alloy silver with copper is used in jewelry of the economy class industry, for the manufacture of kitchen utensils. It contains 87.5% of pure precious metal and looks like white gold.

The color of the material is not as intense as that of the lower samples.

Silver spoons, teaspoons, forks, knives
Silver cutlery

916

Nowadays this alloy is not one of the standard modern samples. The peak of its popularity came during the Soviet era, when it was used to make jewelry, souvenirs, and household items. On such items you can see the imprint of a five-pointed star or a worker's head - the stigma of the Soviet Union era.

Now 916-marked items are of historical value.

The material does not turn yellow because it contains a small amount of ligature.

925

Previously of precious metal 925 proof The word "sterling" was used to coin English coins, hence the name "sterling silver. There is a version according to which the word "sterling" itself came from the family name of the minting family, the Easterlings.

This alloy makes shiny and durable items, and jewelers love to work with it.

In addition to jewelry, 925 silver produces photo frames, saucers, vases and candlesticks.

925 sterling silver
Silver stamped with 925

960

96% of pure precious metal in the composition makes the alloy unstable to mechanical damage. For this reason, protective coatings are applied to products of this class.

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The foundry properties of the precious metal allow you to create a real masterpiece, filigree jewelry that amazes with its elegance.

999

The alloy consists of the purest lunar metal. It is used for minting collector coins and casting bank ingots.

This material is not used for jewelry, as products made of it would be too fragile.

Color samples is as close to white as possible. This is due to the property of silver to reflect light almost completely.

Sterling silver
Sterling silver

Other low-grade silver alloys

The lowest silver assay is the 600 grade. It contains only 60% of precious metal and has a scarlet hue due to high copper content.

The use of silver is known 500 samples, the material was used to mint the Tsar's billon and the German stamp.

Technical silver

"Technical" refers to the precious metal contained in radio components. It can be found in many things around you. For example, a power supply contains about 1.5 grams of technical precious metal.

It is also used in medicine, dentistry, and the space industry. The assay of such material is 600-650.

Technical silver has a number of positive characteristics:

  • The material is soft and flexible;
  • It has a high electrical conductivity;
  • The metal is inert and resistant to corrosion;
  • It has a low melting point;

The price of such precious metal varies about 60 rubles per grams.

Technical silver
Technical silver plate

"Japanese Bronze" Shibuichi

Shibuichi is a precious alloy in the proportion of one part silver and up to three parts copper. The word "shibuichi" itself translates from Japanese as "quarter.

The material is used for making rings, knife handles, brooches, earrings, decorative parts of the Japanese katana sword. Shibuichi can be patinated to achieve original shades of blue, green and purple.

Gilded silver

Gold plated precious metal usually corresponds to the 875 marking or higher. It is coated with a layer of gold a few microns thick.

It is massively used for jewelry, cutlery, creating souvenirs.

To distinguish between gilded silver and gold, you need to look at the markings on the piece. The solar metal may have the following hallmarks 750, 585, З75. On silver - 925 or 875.

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Gilded Silver Jewelry
Men's bracelet in gilded silver

Silver twins

"Doppelgangers" are visually indistinguishable from the lunar metal, but do not contain precious materials. Known replicas are:

Melchior

The alloy formula was obtained in 1819. Melchior contains nickel, iron, and manganese, and is a solid solution that is easy to work both hot and cold.

Melchior is distinguished by its light silver color, excellent casting properties, resistance to corrosion. It is widely used for minting silver-colored coins, creating inexpensive artistic items, and kitchen utensils. Melchior tableware must be silvered, otherwise it will give a metallic flavor.

Neusilber

"Neusilber" in German sounds like "new silver. The composition includes copper, nickel, and zinc.

Neusilver is cheaper than melchior and is widely used for production of enamelware, filigree, wind instruments, and guitar fret. The material has also found industrial application in the production of medical instruments, parts of precision instruments.

The properties of nesilver and melchior are almost identical, nesilver being distinguished only by the presence of zinc.

Neusilber
Jewelry metal nesilver

Silver protective coating for a dazzling shine

Silver metal can lose its former opulence and darken. To maintain its aesthetic appearance, jewelers coat silver pieces with a layer of rhodium, up to one micron thick.

Rhodium is distinguished by its high kindling temperature and resistance to any mechanical influences. It does not oxidize and is highly reflective. That is why rhodium is used as a protective-decorative coating.

Rhodium-plated silver jewelry is similar in value to gold jewelry. Such jewelry is difficult to repair, resize, or recycle because brazing destroys the rhodium layer.

In addition to rhodium, wax or special varnish is used to protect the surface of the product.

Interesting facts about silver

This precious metal has been known to mankind for more than 6,000 years. During this time, many facts about silver have been discovered. Let's look at the most interesting of them.

  1. The metal kills about 650 species of bacteria, but its excess in the body can lead to poisoning, the destruction of DNA molecules.
  2. At the dawn of civilization, silver was revered by many peoples as a sacred symbol of the moon.
  3. The longest silver nugget was found at the Cobalt Mine. It was even dubbed the "silver sidewalk" because it was 32 meters long. The weight of the precious piece was 10 thousand tons.
  4. The dispersal of clouds and other human interference with weather phenomena was made possible by this precious metal.
  5. Silver is used as a food additive in designer restaurants. It is designated as E174.
  6. A little of this metal is found in all mammalian organisms, and the largest amounts are found in brain neurons.
  7. The lunar metal is considered a symbol of purity. It is believed to be able to ward off evil forces, which is why it is used to cast religious amulets.
  8. Seawater contains 10 times more silver than gold.
  9. The precious metal has an almost one hundred percent light reflection coefficient. That is why it is used for cameras and high-end mirrors.
  10. The largest reserves of lunar metal are in India.
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Video: silver refining

Reviews

I had a silver ring blackened. I took it to the shop, and the craftsman treated the surface of the jewelry with rhodium. Now the ring does not tarnish or scratch, and looks even more attractive than before the procedure.

Masha P., Lviv
Maria
Richard N., Vladikavkaz
Boris

I bought a silver bullion bank a few years ago for investment purposes. It weighs a lot of pure silver, I did not even expect that such a small piece could be so heavy. I keep the bullion at home without taking it out of its packaging, so as not to accidentally scratch the soft material.

I began to wonder how much a silver service that I inherited might be worth. I found the 916 mark on it, and it turned out to be a hallmark from Soviet times. It is now of historical value, but I decided to keep it as a memento.

Vasily P, Voronezh
Victor

Jeweler's comment

Molokanov N.M.
Molokanov N.M.
Jeweler, experience in jewelry manufacturing 26 years.
Together copper and silver create a resilient alloy, suitable for creating a huge number of things. The most famous union of these elements is called sterling, and it corresponds to 925 proof.

The alloy of silver and copper is considered the benchmark because copper has less effect on the appearance and physical qualities of the precious metal than other impurities.
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