How often have you encountered this problem: you need welding, but you don’t know what metal is in front of you and, accordingly, it’s difficult to decide on the brand of electrode or filler rod? Perhaps the need to distinguish metal arose for you for another reason.

How can you find out what kind of metal is in front of you, what its grade is without resorting to special studies, such as spectral analysis, or carbon analysis, etc.?

It is not difficult even for a person not initiated into the intricacies of metallurgical science to distinguish non-ferrous metal from black metal. The easiest way you can resort to is a visual inspection.

Black metal when cutting or cleaning it has a silvery-light color, however, it oxidizes very quickly in air. The oxide has a dull gray tint. The metal is easily picked up by a magnet and is highly corroded, that is, covered with a layer of red rust.

Aluminum and alloys based on it - when freshly cut, the metal is light and shiny and cannot be picked up by a magnet; as it oxidizes it becomes dull. Pure aluminum is whitish in color; the oxidized surface is visually perceived as a white coating.

Copper has a red tint, darkens strongly in air with the formation of a green coating. Can't be picked up with a magnet. When burned, the flame turns green.

Bronze - it is an alloy with copper - it has a yellow tint, oxidizes slightly and is not magnetic.

Brass is an alloy of copper and zinc, almost the same as bronze, only it oxidizes more strongly.

Corrosion-resistant steel (stainless steel) without color, sometimes with a grayish tint, hard-worked stainless steel can be taken with a magnet, annealed stainless steel is not magnetic.

Magnesium - metal with a white silver tint, non-magnetic. It burns with a bright white flame and produces a sweetish taste when inhaled.

Various chemical elements, carved with an abrasive or other wheel, burn in air, each in its own unique way. When cutting or sharpening, you can determine the metal more accurately by the color and shape of the spark and the number of “stars”.

It is known that low-carbon steels, depending on the type of deoxidizing agent added to the melt, are divided into: boiling, calm, semi-quiet.

Boiling steel leaves a few long sparks, colored orange. When containing a large amount of carbon (high carbon), a beam of numerous light sparks with “stars” at the end flies out from under the circle. As the percentage of carbon increases, the brightness increases and there are more “stars”.

Tool steel (high-speed cutter) gives a bunch of broken short sparks.

With experience, you can learn to determine the amount of carbon with an accuracy of a tenth of a percent. However, it is almost impossible to distinguish high-quality steel from ordinary steel, since the percentage of harmful impurities such as sulfur and phosphorus, in both cases, is very small and they do not in any way affect the shape, color, size of the spark, etc. . In addition, please note that Art. 20 and St.3, St.4 contain the same amount of carbon and, accordingly, visually you will not see any difference in the nature of combustion.

You can unmistakably determine the presence of tungsten in steel if its more than 3-4% spark turns dark burgundy and this is the main sign that the steel is not carbon.

Cast iron(an alloy of iron with carbon from 2.14%) turns the spark red, you can’t go wrong here.

On impact titanium A bright whitish spark strikes the steel.

Stainless steel gives a similar picture, however, the brightness of the spark is less and it is more difficult to obtain.

Additional research can confirm the brand of material. If you take a steel blank and cut it to 25% of its thickness, and then hit it with a sledgehammer, you will get a fracture, and by studying the nature of it, you can also draw conclusions.

Quick cutter, or rapid(P18, P9 and others) due to its high hardness, it breaks brittlely and the fracture is fine-grained with a dark color. Carbon steel, on the contrary, has a light-colored fracture with a coarse grain. By comparing the data on the type of surface on which the destruction occurred with the results on sparks, we can speak with a high degree of confidence about the correctness of determining the grade of material.

If, despite all the tests carried out, you are still overcome by doubts, then if you have a hardening furnace, you can conduct the following experiment, based on the different ability of steels to harden.

So, steel with a carbon content of up to 0.25% (St. 3-St. 20), after heating to T = 900 degrees, some exposure and subsequent sharp cooling in water, remains as soft and plastic as it was before heat treatment and can be sawed off well a file (it would be nice to have a set of calibrated files with different hardnesses on the farm). Carbon steel with a content of up to 1.3% C can be easily distinguished from low-alloy steel after oil quenching. After such a procedure, the former can be easily sawed with a file, and the latter (alloyed) acquire such a high hardness that the file slides over them (in particular, we are referring to the well-welded grades 9ХС, ХВГ).
It is very difficult to distinguish St.40 and St.50 from St.40X and St.50X from each other by spark, but after hardening, St.40X acquires greater hardness and the file glides over such steel and does not file it down, while St.40 remains soft and pliable. A file, as a means of determining hardness, is used in the absence of other measuring instruments (Rockwell hardness tester, or Super-Rockwell hardness tester with a diamond indenter, or an ultrasonic hardness tester based on the phenomenon of ultrasonic contact impedance).
It should be noted that most steels after hardening have a decarburized layer (this layer, accordingly, has low hardness) and it must be removed to obtain correct data.
If the question is to distinguish steel by type of manufacture, the surface of hot-rolled steel is always covered with a coating of scale, while cold-rolled steel has a clean, shiny, uncontaminated surface.

So, to determine the brand of material, you can resort to one of the proposed options:

• visual inspection,
• striking a spark,
• fracture study,
• hardening and checking with a file.

If you examine a sample of material using all these methods and compare the results, then you can talk about one hundred percent accuracy in determining the grade of material. Also, all these options can be used as additional studies when conducting spectral analysis.

additional information

St.12Х18Н9 (AISI 304) gives a short spark, colored light yellow with a few red dots appearing from time to time. At the point of contact with the abrasive and at the ends of the branching, the spark beam has a red-yellow color.

St.X12F1 - yellow, short spark, multiple “stars”, the ends are elongated in a line. The area where the abrasive touches is red-yellow. Individual red dots throughout the entire beam.

St. 12X13 - light yellow short spark with branches.

Probably everyone had to hold in their hands a piece of jewelry or another object, obviously metal. But how can you determine what metal is used in production? It could be a precious material or a counterfeit, or even a trinket with no claims to value. Expertise from specialists will give you the exact answer, but it is not free. But there are methods for approximately determining the type of metal at home. They were used a long time ago, but they have not lost their relevance in our time.

Bringing a magnet close to the item being tested is a good way to perform initial testing. By the reaction of the magnet you can determine which group the metal belongs to:

1. Ferromagnets. The magnet is clearly attracted to the object, which means that the product may contain iron, steel or nickel.
2. Paramagnetic materials. The interaction with the magnet is very weak. This group includes aluminum and chrome. Among the precious metals that are paramagnetic are platinum and silver.
3. Diamagnets. In general, they do not react to magnets. Copper and zinc have these properties. Precious metals - gold.

Of course, such a check will not allow us to accurately determine the material from which the item is made. After all, a non-magnetic metal may not be in its pure form, but in the form of an alloy with a ferromagnet. But it can confirm or refute the assumption. For example, if it is checked whether it is gold or not, but the item is clearly magnetic, then it can be argued that it is a fake.

When checking jewelry, you should take into account that, in addition to precious metals, they may contain clasps, built-in springs, made of another material. You need to check the metal itself.

Heat check

You can also determine the group of a metal by how it conducts heat. It is known that the thermal conductivity of silver is very high. It is almost five times higher than that of iron or platinum. Slightly worse - for gold, copper and aluminum. Platinum transmits heat even weaker than iron.

If you immerse the metal in hot water for 15–20 seconds, then based on its temperature, determined by touch, you can draw some conclusions.

1. Gold and silver objects will become as hot as the water in which they were dipped.
2. During this time, platinum and items containing iron will become warm, but not hot.

In this way it is easy to distinguish platinum from silver. But it’s not possible to compare silver or aluminum alloy.

Iodine test

You can check the authenticity of the metal using an iodine solution purchased at a pharmacy. A drop of iodine is applied to the surface and left for several seconds. Iodine will not harm noble metals - gold, platinum, silver. If the color of a drop of iodine does not change, and after removing it with a napkin, no traces or stains remain, this indicates the authenticity of the metal. If darkening is visible at the place of the drop, then this is a low-grade alloy or an outright fake.

Vinegar test

Household vinegar solution also does not affect precious metals. And it is dangerous for counterfeits. But, unlike the iodine test, acetic acid takes time. To wait for the result, you need to immerse the metal being tested in a container with vinegar for 15–30 minutes. The absence of traces of interaction between metal and vinegar is a sign of nobility.

If, in addition to metal, the product contains precious or semi-precious stones, then it is better not to check them this way; vinegar can ruin them. This is especially true for pearls.

Dental check

From novels and films we know that they used to test the authenticity of gold coins by biting them. What exactly can be installed in this “old-fashioned” way? Gold is a soft metal. Therefore, even with a weak bite, a dent from the teeth remains on it. Fake alloys do not have this property; you cannot take them with your teeth.

Such a test gives good results for high-quality products. The higher the pure gold content, the softer it is. Gold of 900 purity and higher is so soft that they try not to expose valuable items made from it to contact with other objects.

Expert opinion

Sidorenko Alexander

Antiques appraiser, numismatist

This is how you can compare platinum and silver. The latter does not have the softness of gold, but a strong bite may leave a small dent. It is impossible to leave marks with teeth on real platinum.

Application of chemicals

Testing with active chemical reagents should be left as a last resort. If handled improperly, they will damage even genuine precious metal. And they can be dangerous for the health of the inspector.

Ammonia

Pure gold does not react to ammonia. But practically no products intended for use are made from gold 900 and 999, only for collections. And on a precious metal of lesser purity, ammonia can leave an irremovable mark. Its solution in combination with other substances is used to clean gold items. Therefore, it is not worth identifying gold and silver items using ammonia.

Platinum products are usually produced with a high purity. Therefore, you can check the authenticity of platinum with ammonia. This chemical will not leave a mark on her.

Nitric and hydrochloric acids

Separately, these acids do not affect high-grade gold and platinum. And if you mix their concentrated solutions in a ratio of 1:3, you get a mixture called aqua regia. It can even dissolve gold. Aqua regia does not “take on” platinum when it is cold. This precious metal will gradually dissolve in the heated mixture.

Oddly enough, royal vodka is not afraid of genuine silver. It reacts to it by forming silver chloride in the form of a thin film on the surface. The latter protects the product itself from destruction.

Density check

One of the reliable ways to determine the type of metal or alloy is to determine its density. For pure gold it is two times higher than for copper and almost three times higher than for iron. Platinum is even heavier than gold. Even an alloy of 585 gold is noticeably heavier than base metals.

Of course, to determine the exact density of a small product you will need pharmaceutical scales, volume calculations (Archimedes' law to help) and tabular data on the density of base metals. But to solve the question of what the alloy is mainly made of, gold or another metal, rough estimates are sufficient. If you have at hand an object made of obviously genuine metal of approximately equal volume, then you may not even need a scale. A weight difference of two to three times is not so difficult to catch.

Separately, each of the considered methods will not give an exact answer to the question of what metal the product is made of. But if several different tests show the same results, you can be confident in the correct determination. If not, then you will have to turn to professionals.

Platinum is considered one of the most expensive precious metals, which is used in the manufacture of jewelry. Compared to other noble metals, it is easier to shrink and heat; serves as an optimal material for creating industrial and jewelry products. In the current economic climate, with high demand for jewelry, platinum ranks second after gold.

It emphasizes the social status of the owner. It belongs to the group of white metals, so it is not easy to recognize it among other jewelry.

Metal composition and characteristics

They knew how to test platinum at home back in the 18th century. She was considered a symbol of wealth. Even then, people determined what this piece of white material was needed for. Nowadays, small jewelry is made from precious ingots:

• rings;
• bracelets;
• necklace;
• thin necklaces;
• pendants;
• brooches

Platinum is too expensive a metal to be used to create massive products. The high price per gram can put off buyers, because not everyone can afford a ring weighing 5 grams for one or two thousand dollars.

Modern technologies of our time allow many owners to open online stores of precious goods. But it is impossible to feel and examine the item you like, but you can get acquainted with all the metal quality certificates.

However, some doubt remains, and many are forced to independently check the quality and authenticity of the products. The main difference between platinum is its weight and density.

Density can be compared to metals such as:

• iridium;
• Uranus;
• rhenium;
• osmium.

The metal feels heavier to the touch than other precious alloys. The ratio of the percentage of pure substance is 85-95%. Thus, we can say that platinum products are practically composed of pure metal. The remaining mass of the alloy is iridium and osmium. It is not advisable to add them as weighting agents, since this will not change the price.

The metals are almost identical, the alloys are as precious as platinum. In the mining industry, iridium and osmium are more valuable due to their deposits.

A real platinum product, unlike other metals, is not afraid of iodine. Some chemical elements may not affect the appearance of the jewelry. Alcohol solutions will damage thin coatings or coatings; some oxides will leave a barely noticeable mark on the surface. And stronger concentrated substances completely corrode platinum.

There are not many of them, but the environment also negatively affects the metal:

• the original shine may disappear;
• the appearance will noticeably deteriorate;
• the product will lose its properties.

Compared to silver, a platinum product has a lighter shade. Massive rings and large brooches are not made from expensive metals. This attracts neither customers nor suppliers.

How to distinguish platinum from other metals?

How to determine platinum - the main indicator of difference is the sample. It is always applied to the back of the ring; on chains - to the lock area. Pendants and pendants may not look different at all from cheap metals, especially if the product was inherited. Samples are easily erased, and factory models are supplemented only with documents. Therefore, it makes sense to check the authenticity of platinum.

At home, it is quite easy to distinguish it from white gold or silver. The weight of rings made of different metals will be noticeable - a platinum product is much heavier. There are also alternative methods using chemical units.

Grandma’s method, which is based on the laws of physics, is also suitable: The metal whose density is higher displaces a larger volume of water than the one whose density is lower. And the density of platinum is greater compared to white gold or silver.

How to distinguish platinum from silver - to conduct the experiment you will need a measuring vessel with water. Measure the weight of the product in advance. When placing it in water, monitor the volume of water that is pushed out. If, by the measurements of the glass, the number on the data scale exceeds 21.45 cubic centimeters, then you have a platinum product in front of you. Based on these values, the density of the product can be calculated.

The use of iodine was mentioned above. It will be a good assistant in determining the type of metal. To experiment, apply a drop of iodine to a platinum piece. No changes should occur after this. Household chemicals cannot stain the decoration and are also easily removed from the surface.

The darker the drop of iodine on platinum, the higher the purity of the product. Compare several platinum rings of different grades, focusing on the mark on the reverse side of the product.

There is another way to determine platinum using improvised means at home - “by tooth.” Silver, like aluminum, does not tolerate any impacts or scratches. Platinum jewelry can withstand even the most severe damage. Try to bite (literally) it - if marks remain, it means that this is a fake made of cheaper metal.

Checking with chemical home analysis:

1. Take a dried egg, raw or boiled.
2. Place a silver and platinum ring on top (you can alternate).
3. The silver ring will darken as a result of evaporation and exposure to hydrogen sulfide elements.
4. Platinum jewelry will remain clean.

Temperature conditions for heating platinum are too high.

It is impossible to heat or even slightly melt this metal at home. A professional burner for melting gold will not help either.

Using a lighter, you can change the color of silver - the piece you are testing will darken. Platinum will not even change its shade. With slight heating, the platinum ring can immediately be put on your finger - the temperature allows you to pick it up and you will not get burned.

Source: http://gems-and-jewels.ru/kak-proverit-platinu.html

How to determine copper at home

Copper has a special reddish-pink color. It surpasses all other metals in ductility. Copper wire bends easily even by hand.

You can distinguish copper from bronze in this way: you need to strip the copper wire and lower it into hot salt water for about five minutes, do the same with bronze, then after such exposure the copper will be of a darker shade. Copper also has its own protective layer.

Which appears during prolonged exposure to atmospheric conditions, a greenish protective film appears on copper - patina. When heating copper wire over a gas burner. it will first fade, then darken and turn black. And also apply a magnet, then pure copper does not react to it.

replied 2015-05-19T12:41:40.000000+03:00 2 years, 2 months ago

Other answers below

Is it possible and how to find out the number of neutrons in an atom of a chemical element?

What metals are not magnetic? What metals does a magnet attract?

How to determine what metal (copper, nickel, bronze, brass) a product is made of?

Determined visually by color. If the metal has been lying around for a long time and has oxidized, then look at the fresh cut. Or the surface is slightly cleaned with a file to facilitate visual inspection. They also check with a magnet if the object is simply copper-plated (For example, a wire with a steel core).

replied 2014-01-15T06:24:02.000000+04:00 3 years, 6 months ago

How to determine copper at home?

Copper has a special reddish-pink color.

It surpasses all other metals in ductility. Copper wire bends easily even by hand.

You can distinguish copper from bronze in this way: you need to strip the copper wire and lower it into hot salt water for about five minutes, do the same with bronze, then after such exposure the copper will be of a darker shade.

Copper also has its own protective layer. Which appears during prolonged exposure to atmospheric conditions, a greenish protective film appears on copper - patina.

When heating copper wire over a gas burner. it will first fade, then darken and turn black.

And also apply a magnet, then pure copper does not react to it.

Does unclean copper react to a magnet? By the way, bronze statues also become covered with patina. - more than a year ago

In what sense is it unclean, if it contains 50% iron, then yes, but it is no longer copper. Copper is diamagnetic. Magnets do not attract copper, brass, aluminum or stainless steel. - more than a year ago

How to distinguish bronze from brass at home?

There are a number of ways that will tell you how to distinguish bronze from brass. In the presented material I would like to consider the simplest and most accessible solutions for implementing this task. Let's find out how to distinguish bronze from brass at home.

What is bronze?

Before we figure out how to distinguish bronze from brass, let's find out what each alloy is. Let's start with bronze. So, bronze is an alloy of tin and copper, with admixtures of silicon, aluminum, beryllium and lead. It is the quality of the tin used that largely determines the nature of the future alloy.

There is a special type of bronze, in the manufacture of which tin is replaced with nickel or zinc. This alloy is known as spiater. Essentially, the material is a cheap version of bronze, which is not of the best quality.

According to the above manufacturing principles, bronze is divided into tin and tin-free. At the beginning of the last century, metallurgists produced arsenic bronze. However, due to its high toxicity, the material was never widely used.

What is brass?

Brass is practically the same alloy as bronze. But instead of the alloying composition in the form of tin, zinc is used here in combination with copper. Sometimes lead, iron, nickel, manganese, and other elements are added to the alloy.

The ancient Romans knew how to produce brass. They were the first to learn how to combine molten copper with zinc ore. Pure zinc began to be used for the production of brass only at the end of the 18th century in Britain. The British often used the alloy to create fake gold, because brass, like a noble metal, has an attractive sunny shine.

Today the material is widely used to create the so-called bimetal - an alloy where steel is combined with brass. This solution contributes to the production of metal that is resistant to corrosion and abrasion. At the same time, bimetal products have good ductility.

Defining Differences Between Bronze and Brass

How to distinguish bronze from brass? The difference between the presented alloys is as follows:

1. Brass is produced by combining zinc with copper. In turn, bronze is produced by alloying copper with tin.
2. Bronze can be in contact with sea and salt water for a long time without destroying the structure of the material. Brass requires additional processing in the form of alloying.
3. Bronze has increased resistance to mechanical wear and is a durable material. For this reason, the alloy is widely used to create all kinds of sculptures and monuments. Brass is not suitable for these purposes, although it is used as elements of artistic products.
4. How to distinguish copper from brass and bronze? Copper has a reddish tint. At the same time, bronze has a dark brown color and a coarse-grained structure. Brass has a yellow tint and is a fine-grained material.

Differences between bronze and brass according to weight

How to distinguish bronze from brass based on the weight of the materials? It is worth noting that bronze is a fairly heavy alloy. In equal volumes of workpieces, bronze will be clearly heavier than brass. Therefore, you can distinguish products from individual alloys by weighing them on your palms.

How to distinguish alloys by heating?

You need to try to distinguish between materials using the thermal effect method. However, the results in this case will be more reliable. What do we have to do? It is necessary to heat both alloys using a gas burner to a temperature of more than 600 o C. With this exposure, an ashen coating forms on the surface of the brass product, which is zinc oxide. At the same time, the bronze will remain in its original form.

After heating, the brass will become more ductile. Bronze does not change its physical properties when exposed to high temperatures. If you try to bend a brass workpiece, the structure of the latter will not be damaged. As for bronze, it will definitely break at the bend.

How to distinguish brass from bronze with a magnet?

As noted above, bronze contains tin and lead. These materials can be attracted by a magnet. The only thing required to carry out the experiment is to find a fairly strong magnet. When using it, the bronze will slightly stick to the surface. The magnet will not have any effect on brass.

Finally

As you can see, there are a number of ways that allow you to distinguish bronze from brass at home. In most cases, there are pronounced visual differences between products made from these alloys. Therefore, to cope with the task, sometimes it is enough just to carefully consider both materials.

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Determining the authenticity of copper using improvised means

Copper is a widespread metal, because man was one of the first to master it. Due to its ductility, malleability and high strength, copper has long been used to make weapons, kitchen utensils, jewelry, coins and art objects. Today, since it is also the best conductor of heat and electricity, it is most often used in the production of electrical products.

In nature, it can be found both in nuggets and in the form of compounds. In order to correctly determine the authenticity of copper at home, it is important to remember that its properties are greatly influenced by the content of any impurities. In its pure form, it has a number of characteristic features; you just need to figure out how it differs from other metals.

Main settings

First, copper is reddish-pink in color. Over time, it can change from a red-brown to a reddish-orange hue. If the metal has been lying around for a long time and has oxidized, then it is better to look at the color on a fresh cut. Or the surface should be lightly cleaned with a file so that the original texture is better visible.

Plastic

This is a very soft plastic material. An object made of copper (for example, wire) bends easily without breaking or crumbling. It is not at all necessary to bend or wrinkle the product. You can apply a little force, apply pressure and understand how malleable the metal is in front of you.

Copper is a very photosensitive metal and has high anti-corrosion properties. If it is exposed to the open sky or in a humid environment for a long time, it changes color. Covered with green film. which protects copper products from rust. And further spread of corrosion in depth.

If visual inspection isn't enough to determine authenticity, there are a few other tricks you can use to check the authenticity of the copper.

Heating

Using a gas torch, stove, or a simple lighter (it all depends on the size of the object), thoroughly heat a piece of metal. Copper first tarnishes, then becomes progressively darker and eventually turns completely black as a layer of copper oxide forms.

An ordinary magnet can also help determine the authenticity of a copper product; pure copper does not react to it at all.

Nitric acid

If nitric acid is dropped onto pure metal, it turns blue-green.

There are many alloys based on copper. How to distinguish one from the other?

Distinguish copper from brass

Brass is an alloy of copper and zinc. Not surprisingly, visually they are very similar. The more zinc in the alloy, the lighter the brass. So copper is definitely redder.
In addition, brass is a harder metal; it is difficult to bend without additional heat treatment (casting). So we try to bend it or check for a tooth.

Brass is also lighter. Electrodes for the plug of any electrical household appliance are made of brass. So at home there is always something to compare with.

Distinguish copper from bronze

Bronze is an alloy of copper with tin and other elements, most often has a reddish-brown color. These two metals are also very similar in appearance. Remember that all its alloys, compared to copper, are always much harder.

To determine, you need to prepare a hot saline solution. Then either pour it onto a previously cleaned surface, or dip copper wire into the solution for a while. The same should be done with a bronze product. When exposed to hot salt water, the shade of copper will become much darker compared to bronze.

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How to distinguish scrap brass from scrap copper

Brass and copper are metals that look very similar. Brass is an alloy of copper and zinc, so it can sometimes be difficult to immediately distinguish one from the other. Brass is a hard alloy used to make household items, while copper is a ductile metal and is mainly used in the electrical industry. To distinguish, you will need a plug from the cord of a household appliance.

1. Look at the color of the plug electrodes. They are made of brass. Keep in mind that the color of brass varies from reddish brown to silvery yellow. Brass becomes lighter when more zinc is present in the alloy. Compared to copper, brass is lighter. Copper is a reddish-brown metal, new copper is reddish-orange in color. Rusty copper turns green.

2. Bend a piece of copper wire. Copper is soft and ductile. Brass is harder than copper. Brass is difficult to shape without casting or stamping.

3. Brass is used to make various household items such as pipes, musical instruments, picture frames, radiators and hardware items. Copper is mainly used for electrical wires and other types of electrical conductors.

Attention, TODAY only!

Source: http://sovetskyfilm.ru/all-1684/

How to determine the authenticity of silver at home?

Silver is a noble metal from which both jewelry and household items and dishes are made. Although silver items are counterfeited much less frequently than gold items, sometimes there is a need to verify the authenticity of an item that is in your home or purchased for an occasion. We will tell you in this article how to determine the authenticity of silver at home.

How to determine the authenticity of silver?

In its pure form, silver is a very soft metal, so products made from it will be fragile. One of the purest samples, sterling silver, consists of 92.5% silver and 7.5% copper.

The alloy is much harder than pure metal, which allows it to be used in the production of coins, jewelry and other household items. Each product that is positioned as silver must be marked with a hallmark indicating the purity of the metal.

However, if there is no mark on an item, this does not mean that the item is not silver, it is simply made in a country where the mark is not required or the item itself is not certified.

Important! To determine the quality of a silver item with markings, arm yourself with a magnifying glass and study the numbers on the mark. According to international standards, the product is marked with numbers: 925, 900, 800. The numbers show the percentage of silver in the alloy:

• The number 925 means that the alloy is 92.5% silver and the rest is copper.
• Stamps 900 and 800 mean that the product is 90% and 80% silver, respectively. Such alloys are considered coin alloys because they contain a high proportion of copper.

Sometimes even the presence of a stamp with numbers does not fully guarantee the authenticity of the product. Therefore, it is better to use the physical properties of the metal and test the item at home. Let's look at the basic simple methods that will help answer the question of how to test silver at home.

Method number 1. By appearance

Real experts are highly likely to determine the authenticity of silver by eye:

• The metal reflects light well, so it shines a lot. The metal color is silver-white. If the product is not cleaned, it becomes covered with a dark film and becomes dull, with a pink tint.
• If you rub cupronickel silverware, a metal of a different color (usually pink) will appear under the whitish top layer. Chrome has a bluish tint, and nickel alloy has a yellowish tint. Silver does not change color - it remains white both inside and outside.
• Check authenticity by touch: hold the item in your hand. Since silver conducts heat very well, after some time its temperature will become equal to the temperature of your body.
• You can distinguish silver from aluminum by weight: silver is denser, therefore, in your hand it will be much heavier than aluminum, since the second metal is very light.
• The product, which many scammers add zinc to, will leave a slightly noticeable residue on your hands. Rub your finger on the silver jewelry: if your hand remains clean, then this is a genuine product, and if a darkened coating from zinc remains on your finger, then a very small amount of noble metal is mixed with zinc in the product.
• If you have good hearing, then throw the object from a small height onto a hard, flat surface. The sound when falling should be ringing, loud, vibrating, but not dull.

Method number 2. Checking magnetic qualities

If you are just planning to purchase jewelry, you can use a magnet to determine its authenticity. Run a magnet over the decoration.

Important! A genuine noble metal is classified as diamagnetic and will not be attracted to a magnet.

If you need to check the authenticity of a metal ingot, then use a magnet as follows:

1. Place the silver bar so that its smooth side is inclined at 45 degrees.
2. Place a magnet on the smooth side.

Important! On a genuine bar, the magnet will slide down smoothly. The magnetic field of the magnet creates a braking effect, which slows down the sliding.

Method No. 3. Ice check

Silver has the highest thermal conductivity of all metals. The ice test works well on bars and coins, but poorly on small jewelry. Use this method if you are faced with the question of how to check a coin for silver left over from past generations.

Keep the ice in the freezer until the test is completed, and then proceed as follows:

1. Get the ice.
2. Place a piece of ice on the silver object.
3. Watch the ice carefully: it will melt as if it were placed on something very hot, although the metal itself is at room temperature.

Important! If you notice that the metal has begun to change color over time, this may not be a sign of poor quality. Read in more detail in our separate publication about why a silver cross or other decoration made of such an alloy turned black.

Method number 4. Chalk check

This is one of the simplest methods for determining the authenticity of a metal:

1. Rub the silver item with chalk.
2. If the chalk turns black, this means real silver.

Method No. 5. Using a lapis pencil

Instead of chalk, you can use a lapis pencil to determine the authenticity of silver at home:

1. Wet the surface of the object.
2. Drag the tip of the pencil over the metal.

Important! After a few minutes, the noble metal should darken at the point of contact with the pencil.

Method number 6. How to test silver with iodine

Very few substances can attack noble metals. Iodine has the following properties. If you anoint genuine silver with iodine, a stain will form on it. The greater the concentration of silver in the alloy, the blacker the stain will be and the faster it will form.

Important! Use this method very carefully, as you can ruin a beautiful product. To experiment, choose an inconspicuous area and apply a minimum amount of product with a cotton swab. After applying iodine, immediately wipe it off with a cotton pad. And you can start cleaning silver from yellowness.

Method No. 7. Using sulfur ointment

Sulfur ointment is sold at the pharmacy. To check the authenticity of the metal, proceed as follows:

1. Lightly rub the piece with fine-grit sandpaper.
2. Apply a small amount of ointment to the surface.
3. Leave the item for 10-15 minutes.
4. Inspect the surface: a dark spot will indicate authenticity, but nickel and stainless steel will not have such spots.

Important! The method using sulfur ointment is risky, but effective. If silver has turned black under the influence of sulfur, you can return the item to its original color by boiling the item with pieces of aluminum foil and adding soda.

Method No. 8. Hydrostatic weighing method

This method is based on Archimedes' law. To implement this, you need accurate scales. The essence of the method:

1. First, weigh the item in the usual way and determine the dry mass.
2. Immerse the product in water and determine the mass in water.
3. Divide the dry mass by the difference between the two masses and get the density of the metal.
4. The density value for silver should be 10.5. If the density is about 7, you most likely have tin.

Did you know that today there are already many technologies for effectively and quickly cleaning precious metals? If you have a lot of such items, be sure to read about ultrasonic cleaning of silver.

Method number 9. Chemical test

This method is used if you need to determine the authenticity of silver, but the product does not have a stamp. This method is used extremely rarely at the household level. It is used mainly by jewelers and laboratory workers. But if you decide to study chemistry, then buy a regular “silver test” reagent and rubber gloves, since you will have to work with caustic acids.

Instructions for use of the reagent:

1. Remove the thinnest layer of silver coating from the object. To do this, run the file over the surface once.

Important! If you do not want to leave scratches on the product, then use a touchstone. You can purchase it from the same place as the test reagent kit. Rub the object against the stone to create a relatively large residue of metal (a few centimeters in length). In this case, apply the acid to the mark left on the stone.

1. Prepare test acid: 1 part pure nitric acid and 1 part sodium dichromate or use a ready-made test.
2. Apply acid to the part of the product from which a small layer of metal has been removed.
3. The surface will become shiny, as if it had been polished.
4. Evaluate the test results. Pay attention to the color of the surface on which the acid is applied. A color scale is included with the instructions for using the test. Typically, it looks like this:
   • Bright red color - pure silver.
   • Dark red - 925 silver.
   • Brown - 800 standard.
   • Green - 500 standard.
   • Yellow - tin and lead.
   • Blue - nickel.
   • Dark brown - brass.

Important! When regularly updating your jewelry arsenal, take care of proper care of them. We have already thought about this in advance. Choose suitable methods from our selection for how to clean silver at home.

material

All available and known methods have one significant drawback - they are superficial and do not provide a 100% guarantee that the product is not silver plated. To make sure that an item is made of silver, you need to make a cut and check the quality of the precious metal at the cut site. Therefore, there is only one piece of advice - try to buy silver products in trusted places. Let your life be genuine!

Eleanor Brik

The fear of being deceived haunts many people, and this fear is not unfounded. According to statistics, over the past 10 years the production of precious metals has practically not increased, but at the same time the number of jewelry stores is growing at an incredible pace. Alas, even when buying jewelry in a jewelry store, there is a chance of running into a low-quality fake. Are you overcome by doubts? Verifying the authenticity of precious metals is available not only to specialists, but to each of us. There are many ways to do this, which can be done at home.

All that glitters is not gold

Only a jeweler who has all the necessary analytical equipment can check a gold item and issue a reliable conclusion as to whether it belongs to a noble metal. Professional verification is carried out by the Assay Office. Examination of gold jewelry is not a cheap pleasure; the price of the service ranges from 10 to 20% of the estimated value of the product. They are counterfeiting more and more often, and no one wants to waste money. By the way, the need to check gold for authenticity may arise not only in relation to jewelry, but also, for example, when purchasing bars or nuggets.

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The most difficult type of counterfeit to independently identify gold is a piece of jewelry on which a thin layer of precious metal is applied. It is extremely difficult to determine the authenticity of such work at home without causing damage to the product.

The most common methods of counterfeiting gold items:

• surface gilding;
• replacement with copper;
• alloys of aluminum and other metals;
• an alloy of titanium and gold.

Fake jewelry made from alloys similar in color to gold leave spots on the skin with a green tint, especially when the ring is worn for a long time. The substitution of less valuable metal alloys for gold by others or similar deposition can be determined using well-known methods.

The first stage is checking gold by comparison. Surely you have a piece of jewelry whose authenticity you have no doubt about. A line should be drawn on a hard object with these two decorations. Gold items will leave the same mark, but if there are differences, this is a direct reason to doubt the quality.

Using a magnifying glass, look closely at the mark, which should reflect the gold standard. It should be clear and without damage.

The cost of a gram of gold changes daily, however, you should rely on it when purchasing jewelry, even if it is not purchased in a store.

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There is also an opinion that sound helps to identify a copy. Gold items emit a crystal ringing sound when they hit a hard surface. A dull or any other sound is a cause for concern.

Iodine test

Iodine can change the color of most components that are used to falsify precious metal, but this test is completely harmless for jewelry with a purity above 500 (i.e., which contains more than 50 mass percent gold).

A drop of pharmaceutical alcohol solution of iodine should be applied to the product that is in doubt, and after 10-15 seconds, remove its remains with a napkin. If a trace of iodine remains, then this is not a gold product. Unaltered metal color may indicate authenticity.

Magnet check

Precious metals are not affected by magnets. Steel products coated with a thin layer of gold will instantly be attracted to the surface of a magnet; real gold jewelry will not react to a magnet.

Many manufacturers use lock designs for chains and bracelets that include a steel spring - in this case, the magnet will only attract the lock.

Indifference to a magnet is a necessary condition, but not a sufficient one. For example, most alloys of copper and tin are non-magnetic. However, such products are much lighter: the difference in weight can be felt even without an analytical balance.

Vinegar test

A cheap fake will turn black when exposed to acetic acid. If you lower it into it with a sample above 500, then nothing will happen to it. This is another surefire method of recognizing authenticity. 3-5 minutes is enough to conduct the experiment.

By the tooth

You've probably seen in films how the main characters tried a gold coin "by tooth." This method is only suitable for high-grade gold (whiter than 900), which is relatively soft. On such gold, teeth marks will definitely remain, since its hardness is much lower than that of other metals.

Determining the authenticity of gold using analytical instruments

Instant identification of metal components at home is possible using a special device called a metal analyzer. The result is displayed on the screen within 2-3 seconds. To obtain it, you need to point the device at the object under study. The analyzer is widely used by precious metal miners.

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In order not to doubt the authenticity of gold jewelry, you should choose the right place to purchase it. Jewelry stores and pawn shops are selling points for real precious metals. Buying second hand is always a risk.

Authentication of platinum jewelry: your own expert

Platinum is a precious metal used in jewelry making. The silver-white metal gained its fame back in the 18th century, but only in our time has it become widely used by jewelers. As a rule, only small jewelry such as rings, earrings and chains are made from platinum. This is due to the high cost of the material.

With the spread of the Internet, purchasing jewelry has become much easier. However, you will not have the opportunity to examine the product before purchasing, which means you may encounter a fake. Many people prefer not to take risks by purchasing jewelry in specialized stores, but even in this case you are not immune from counterfeiting. So how can you independently verify the authenticity of jewelry made from platinum?

Determination of product weight and density

Platinum is a heavy metal, the weight of which is comparable only to iridium, osmium, rhenium and uranium. All other elements are easier. In addition, in the production of jewelry, the specific gravity of platinum ranges from 85% to 95% of the total weight of the product. That is, jewelry is almost 100% made of this noble metal. Products made of gold and silver, for example, contain much less precious metal.

The use of iridium, osmium and rhenium to make jewelry heavier is inappropriate, since these elements have the same cost as platinum, and they are rarely found in nature. Pick up a platinum ring and a similar-sized ring made of another metal. A product made of platinum will be heavier than a similar piece of jewelry made from a different alloy.

May 26, 2016 at 12:42 pm PDT

If you have a suitable measuring vessel, you can measure the density of the product. To do this, you need to weigh the precious accessory, and then place it in a bowl of water and determine the volume of displaced liquid in cubic centimeters. After this, the weight of the decoration in grams should be divided by the value of the water displaced by it in cubic centimeters. The resulting value should be close to the number 21.45. In this case, we can say with complete confidence that the platinum jewelry is genuine.

Use of chemicals

• Iodine. Take regular medical iodine and drop it on a platinum product. The drop must have a dark color; only in this case can we talk about the authenticity of the noble metal. The darker it is, the higher the standard of the jewelry. There should be no streaks left on the accessory. Also, no stains will remain from acetic acid and hydrogen peroxide.
• Ammonia. All precious metals except platinum react to the effects of this substance. Only it does not turn black and does not react with ammonia.
• Nitric and hydrochloric acid. These chemicals should be mixed in a 1:3 ratio to obtain aqua regia. When heated, this mixture will slowly dissolve the platinum product. When cold, no changes will occur.

How to distinguish platinum from silver

Silver is much cheaper than platinum, so some careless manufacturers sell silver products under the guise of an expensive precious metal. To distinguish a fake, you first need to consider the color of the precious jewelry. Platinum is a lighter metal, while silver has a gray tint. In addition, due to the high cost of platinum, large items are not made from it. If you are offered a massive chain at a bargain price, then most likely they are trying to deceive you by selling a silver accessory.

You can try both products on your teeth. There will be nothing left on the platinum, while there will be a slight mark on the silver. This is due to the fact that platinum has a higher density. In addition, these elements enter into chemical reactions in different ways, for example with hydrogen sulfide. At home, you can use a rotten egg, on which you should place jewelry made of two metals in turn. Silver will turn black under the influence of hydrogen sulfide, but nothing will happen to platinum.

Heating the product

Platinum is a refractory metal, so it cannot be melted with a regular lighter, the flame of a stove or a gas burner. Platinum jewelry will not change color even with strong heat. By the way, platinum has a rather low thermal conductivity, which means that a product made from it will heat up longer than, for example, silver and gold, but it is very problematic to draw any conclusions based on this property.

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If you still doubt the authenticity of platinum jewelry, then the best option is to contact a professional. Then you will have no doubts and you will be sure that your jewelry is made of noble metal.

Self-authentication of silver jewelry

Silver is a noble metal, the properties of which were appreciated many centuries ago. Pure silver and its alloys are widely used in the manufacture of jewelry, dishes, cutlery, and instrument making.

Try

The cost of silver is quite high, and, by the way, recently the prices for this metal on world exchanges have been constantly growing. It is not surprising that the number of counterfeits and falsifications is also increasing. When buying silver items, first of all you need to pay attention to the sample. It is quite difficult to fake it: only top-class specialists can make a cliche. On the surface of the product, the sample should be clearly readable, with smooth, clear outlines. The hallmark on Russian-made silver products has the form of a rectangle, inside of which is printed a three-digit number indicating the proportion of chemically pure silver in the product.

The amount of impurities determines the quality of the metal. The most common hallmarks are: 720, 750, 800, 875, 916, 925, 960. Hallmark 720 means that the jewelry alloy contains 72% silver, 750 – 75%, and so on. From this dependence it follows that the higher the sample, the higher the cost of the product.

Alloys 750 and 800 contain a lot of copper, which is why they have a yellowish appearance. Cutlery is usually made from them. Silver of this standard is susceptible to oxidation, so you will have to clean spoons and forks quite often.

High-quality silver used for the production of jewelry has a purity of 925 and higher.

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Authentication

If there is no hallmark on a product passed off as silver, you can ask a jeweler for a determination, for example, take it to a pawnshop and ask for an appraisal. In addition, there are many ways to check the authenticity of an item yourself.

Express methods for determining the authenticity of silver at home

• One sure way is a magnet: silver should not be attracted. However, this test alone is not enough: many alloys that imitate silver also do not have magnetic properties.
• To determine, use sulfur ointment, which can be purchased at any pharmacy. The product should be spread in a thick layer and allowed to sit for a couple of hours. Genuine silver or an alloy with a high content of this precious metal will definitely turn black.
• Iodine test. Under a drop of an alcohol solution of iodine, silver also blackens, and the higher its quality, the stronger. But here you need to act carefully, these manipulations can lead to damage to the item, since it will be very difficult to remove the stain.
• Silver-plated brass or copper is often passed off as silver. You can make a scratch in an inconspicuous place: if a reddish or ginger tint appears on the edges of the cut, it is a fake.
• Silver bends quite easily, and after stopping the impact it does not restore its shape (silver-plated copper and brass have little spring, because they have high elasticity).
• Silver has high thermal conductivity. An item placed in hot water instantly heats up. It also quickly takes on the temperature of the human body.
• When wearing fake jewelry, dark streaks remain on the skin. This indicates the addition of much cheaper zinc. Jewelry made from such alloys is very fragile and often breaks.
• Silver has a specific smell; people with a sensitive sense of smell can determine the authenticity of the product.

All these verification methods are quite superficial and can only be used for a preliminary assessment. Only an expert jeweler can guarantee that the product is made of silver, and not just silver-plated. To ensure 100% authenticity, you will have to make a notch or carry out calculations with specific gravity.

May 28, 2016 at 8:30 PDT

Real silver darkens over time. But this takes years, and besides, its shine can be easily restored. To do this, use a special cream or ammonia. The shine of low-quality products disappears forever.

Silver test

One of the most accurate methods for determining the authenticity of silver at home is a silver test, which can be purchased in specialized stores or online. By following simple instructions, with a high degree of probability you can determine not only the authenticity of the product, but also the approximate sample.

There are electronic devices that can distinguish silver, gold, white gold, and platinum. However, their cost is so high that purchasing them for the purpose of one-time determination of precious metals at home is not economically justified.

Finally

Counterfeiting precious metals is one of the most common methods of fraud. The increase in the number of falsifications is explained by the high income of fraudsters and the difficulty of suppressing activities of this kind. That is why you need to approach your purchase seriously. Only specialized stores that work directly with manufacturers can guarantee the safety and quality of products made from precious metals.

19 November 2014, 17:18