What is a synthetic diamond? What is a synthetic diamond?

In recent decades, technologies for the artificial cultivation of precious stones and their analogues have been actively developing. Of course, most of all, manufacturers, jewelers, and buyers are interested in the possibilities of producing the king of precious stones - diamond, which is due to its price. The high price of natural diamonds is associated, first of all, with their properties, such as phenomenal hardness, excellent ability to refract and return light, which ensures the sparkle and play of a cut diamond. But there is another important factor - significant monopolization and closure of the diamond mining market, which does not allow the price of stones to fall according to the natural market laws of competition.

Recently, laboratories have developed several technologies for growing synthetic diamond, the most common two of them:

1. In a chamber at high pressure (50-60 kilobars) and temperature (about 1400-1600 degrees Celsius), which has the abbreviation HPHT (High Pressure, High Temperature), growing an artificial diamond of about 1 carat using this technology takes about 5 days.
2. Chemical deposition (CVD). The most popular variation of this process is microwave plasma vapor deposition (MPCVD), using a mixture of methane and hydrogen gases as the starting material.

Manufactured artificial diamonds have a number of disadvantages:

1. The main drawback is the color. It is quite easy to synthesize richly colored stones (yellow, blue, green, pink, etc.), but the problem of producing perfectly colorless diamonds still remains unsolved. A standard artificial diamond has a color I-K on the GIA scale, which corresponds to color 6-7 according to the Russian TU standard. This means that the synthetic diamond has a clearly visible yellowish tint. Recent advances in HPHT and CVD technologies have made it possible to obtain G-H color, i.e. 4-5 color according to specifications, but the complexity of production does not yet allow the prices of such stones to drop significantly below the prices of natural diamonds of similar characteristics.
2. Foreign matter, metallic for HPHT and black strands of unconverted carbon for CVD.
3. Presence of metal impurities for HPHT; nitrogen, silicon and hydrogen for CVD - which allows you to easily identify the synthesized stones by spectrogram.
4. Presence of characteristic fluorescence.

Despite the noted disadvantages, modern high-quality synthetic diamonds are difficult to distinguish from natural ones even by an expert in a jewelry store or pawnshop; only a laboratory can do this. The main disadvantage of artificial diamonds remains their high price, comparable to natural stones of the same quality.

A very common misconception is that cubic zirconia is a synthetic diamond. This is fundamentally wrong; a synthetic diamond is no different in composition from its natural counterpart, that is, it is a carbon crystal. Cubic zirconia is a cubic crystal of zirconium dioxide, synthesized for the first time by the Lebedev Physical Institute; it is often confused with the natural stone zircon, which, in turn, is a crystal of zirconium silicate. Cubic zirconia has two significant disadvantages:

1. Low hardness, due to which it loses its shine, scratches and chips.
2. The relatively low refractive index is why light can often be seen through cut cubic zirconia, which gives the feeling that you are holding a glass fake in your hands. A well-cut diamond or moissanite does not allow light to pass through, allowing for complete internal reflection of light.

Cubic zirconia is currently a very cheap stone, the market price of which is about $50 per kilogram, i.e. less than half a ruble per carat. Thanks to this fact, cubic zirconia is very beneficial to insert into various jewelry and decorate clothes with it. Some unscrupulous sellers confuse buyers by calling cubic zirconia Brillianite and other misleading names, while unjustifiably raising prices for jewelry with them. Buying gold jewelry with cubic zirconia is not very wise because of the low service life of cubic zirconia, which noticeably fades in 1-2 years due to micro-scratches and abrasions. However, the new well-cut cubic zirconia is quite close to a diamond in its jewelry properties, i.e. capable of delivering impressive sparkle and play.

Nevertheless, cubic zirconia in its sparkle and play compares favorably with Swarovski crystals, which are crystal, i.e. glass with the addition of lead oxide. The addition of lead allows them to achieve some shine and play, but they are very far from being a diamond or even cubic zirconia. Daniel Swarovski's genius was to put a backing of aluminum foil under a penny crystal rhinestone, which would reflect the light "flowing" through the crystal, making it appear brighter. Neither a diamond, nor, especially, moissanite need such tricks, because... Being well cut, they return all the incoming light back up into the eyes of the observer, giving them outstanding brightness and brilliance.

It has become widespread in recent years as a new jewelry stone very similar to diamond. This stone is a silicon carbide crystal first discovered by French chemist Henri Moissan in 1893, which was named after him in 1905. In its natural form, moissanite occurs in very small grains and in meteorite matter. Several years ago, the American company Charles & Colvard patented a method for producing synthetic gem-quality moissanite. Moissanite is most notable for its superior refractive index and dispersion properties to diamond, allowing it to sparkle and sparkle more than diamond. In addition, it is practically not inferior to diamond in hardness, i.e. does not scratch or fade, unlike cubic zirconia.

Colorless moissanites have color characteristics comparable to artificial diamonds, i.e. I-K (6-7) for regular moissanite and G-H (4-5) for HPHT treated moissanite. HPHT refining permanently improves the color of the stone by restoring broken bonds in the crystal, and in this process the stone even becomes slightly stronger. In addition, moissanite has physical properties, such as density and thermal conductivity, very close to diamond, which does not allow it to be distinguished by standard Diamond Tester devices; this requires special moissanite testers, which are not yet so common.

In addition to its optical properties, an important advantage of moissanite is its price. With a similar stone size, the price of moissanite will be an order of magnitude lower than both natural and synthetic diamonds. In addition, moissanite can be made of almost any size, unlike synthetic diamonds, the weight of which is currently limited to values ​​​​of about 1.5-2 carats.

Note! Currently, the only manufacturer of high-quality jewelry moissanites is the American company Charles & Colvard; the technology for the production of synthetic moissanites is patented throughout the world, incl. and in Russia. The patent does not apply to a number of Asian countries, such as India and Thailand, which currently openly sell their low-quality moissanites on the Internet. When buying a synthetic jewelry insert - moissanite, always check with the seller for a plastic card-certificate from Charles & Colvard, which gives you the right to a lifetime guarantee!

We hope that our article will help you make the right choice of stone to set in your jewelry.

We invite you to visit the widest catalog of jewelry with moissanites in Russia on the website of our online store Bright Spark. In our articles you can learn more about

Scientists at the All-Union Scientific Research Institute for the Synthesis of Mineral Raw Materials encountered an unexpected phenomenon. They grew artificial diamonds using the usual method of high temperatures and pressures.. This time, the purpose of the experiments was to find out how excess nitrogen affects the properties of diamond, and in order to introduce more nitrogen into future crystals, from 5 to 20% of manganese nitride Mn 4 N was added to the mixture of metals - carbon solvents.

The resulting crystals actually contained more nitrogen than usual (by two to three orders of magnitude!). These were real artificial diamonds However, there were very few ideally shaped single crystals with a cubic lattice among them. But almost 20% of all diamonds turned out to be twin intergrowths, and not single crystals. Some anomalies of physical characteristics were also observed, in particular weak anisotropy (inhomogeneity) of optical properties.

Most “deviations from the norm” are explained by stresses that arise in the crystal lattice due to the addition of nitrogen. But how to explain the unusual color of most crystals? The researchers obtained not yellow, as usual, but dense green transparent artificial diamonds.

Application of artificial diamonds

Diamond glass cutters

Using diamond to cut glass is the most ancient practical use of this mineral. The most common tool for this purpose is a diamond glass cutter, which consists of a diamond crystal cut in the shape of a regular tetrahedral pyramid, fixed in a metal holder, and a brass hammer with a wooden handle. For the manufacture of glass cutters, diamonds weighing 0.02-0.20 carats with a dense structure without defects are used.
Depending on the thickness of the glass, different glass cutters are used. For example, glass cutters are used to cut glass up to 5 mm thick, where the weight of the crystal is from 0.02 to 0.12 carats, and with a thickness of up to 10 mm - from 0.12 to 0.20 carats.
The performance of a diamond glass cutter is very high. A diamond weighing 0.1 carats, for example, can cut 100,000 linear meters of glass. Carbide glass cutters do not provide such productivity.

Dental instrument

In addition to the listed methods of technical application, diamond is also used in medicine, mainly in dental treatment.
Tooth enamel is close to quartz in hardness. Therefore, very hard materials are required for its processing. The tools used with silicon carbide have insufficient hardness; in addition, they cause pain. The use of diamond tools eliminates these disadvantages.
It becomes possible to significantly increase the number of revolutions of drills for processing a tooth with a low pressure force on it. Pain when using a diamond tool is reduced to a minimum.
We briefly talked about the most important areas of application of diamonds in technology. However, this does not exhaust all areas of its use. Diamond is used for many other purposes, and this area of ​​its use is increasing every year.
The use of diamond in technology can dramatically increase labor productivity and reduce production costs, facilitate production automation processes, obtain parts of exceptional precision and cleanliness of finish, and also save huge amounts of money.
Finally, the man found a real place in life for the diamond and made it work for himself. And for us now, a diamond in work overalls is much more valuable than a diamond in a sparkling crown.

Diamond drawing

The drawing process is a method of processing metals by pressure, which consists of drawing rolled, or less often forged, products of a round or shaped profile through a hole whose cross-section is smaller than the cross-section of the original product. As a result of drawing, the transverse dimensions of the product decrease and the length increases. This process is especially widely used for the production of thin wire from non-ferrous metals. The method of metal processing in question was known as early as 3-3.5 thousand years BC. In those distant times, drawing was used to make gold and silver wire for jewelry. This kind of wire was called gimp. Hence, the expression “pull the ropes” has firmly entered into our everyday life, that is, to do something slowly, monotonously.
This expression was explained by the technology of making wire in ancient times. Then all the equipment consisted of a drawing board fixed between two posts and pliers, which were tied to the belt of a worker sitting in a swinging cradle. The worker pulled himself up to the drag, grabbed the end of the wire passed through it with pliers, rested his bent legs on the posts and, straightening them, pulled the wire. He swung until he pulled out a wire of the required diameter and size.
In order to draw wire of the required diameter, the dies must be made of a very strong material that is difficult to deform. The dies were made of hard alloys, which could not withstand stress for long and quickly failed.
With the introduction of diamonds into technology, diamond dies (dies) began to be used for drawing thin wire. Through such dies it became possible to pull wire of precise diameter - from 0.001 to 2 mm.
The use of diamond dies ensures high surface quality and precision in the diameter of the drawn wire, since diamond is difficult to abrade. With diamond drawing, you can obtain thin wire with a diameter of 9-10 microns. The durability of diamond dies is 100-300 times higher than that of carbide dies, depending on the die diameter. When drawing copper wire, the durability of diamond dies, expressed in kilometers of drawn wire, is 25-30 thousand km, while the durability of carbide dies is only 100 km. Through one diamond die you can stretch a wire of such length that you can encircle the globe along the equator several times.
Diamond die is a diamond crystal cut in three planes, fixed in a metal frame, with a channel drilled in the center and polished.
The weight of the diamond for the dies is selected depending on the diameter of their holes. GOST 6271-60 sets the weight of crystals for dies.
Wire drawing at domestic factories is carried out using single and multiple drawing machines. In the first, the wire is pulled through one die, and in the second, through several successively located dies. The most widely used machines are multiple drawing machines, which are characterized by high productivity.

Diamond tips

The modern level of mechanical engineering is characterized by the use of a wide variety of high-strength and wear-resistant materials. Their important quality is hardness. Therefore, in the industry related to the processing of metals and minerals, hardness tests are most widely used.
Several methods are used to determine the hardness of metals and minerals. According to the Brinell and Rockwell methods, the test is carried out by pressing a steel ball into the material being tested; according to the Vickers method, a pyramid-shaped diamond crystal is used for this purpose; According to the Mohs method, hardness is determined by scratching a mineral; metals and minerals are determined by their resistance to deformation when a ball or pyramid is pressed in. In this case, a certain deformation occurs not only in the material being tested, but also in the one being tested. Diamond is not subject to deformation and therefore it meets the requirements for the design of instruments for determining the hardness of minerals and metals.

We will leave the question that artificial stones do not have the properties of natural ones for another article. Let’s immediately look at how and why people create artificial diamonds.

Types of artificial diamonds

As you know, diamond is the most durable of precious stones; nature “spends” at least several thousand years to create it, and also “applies” high temperature and pressure. Only in the 14th century did they learn to cut them and the very concept of “diamond” appeared, i.e. cut diamond. The man’s inquisitive mind did not stop there. Attempts to create an artificial diamond began already in the 18th century.
In total, several types of synthetic stones are currently known, similar in appearance and structure to diamonds.

• Moissonite - grown in laboratory conditions since 1905, its composition is silicon carbide. The mineral is named in honor of its creator, the French scientist Henri Moissan. Further, technologies were significantly developed in the Soviet Union and the techniques and methods developed by Soviet scientists are still used. The value of moissonite in industry is very high. In terms of its technical characteristics, it can even surpass natural stone.
• Swarovski crystals are crystal with a modified composition. Swarovski is a world famous brand. Daniel Swarovski began his work in the mid-19th century, when he invented his own formula, which allowed him to obtain crystals that were ideal in brilliance and beauty.
• Cubic zirconia - Soviet scientists obtained this mineral in 1968. Named in honor of its “parent” - the Physical Institute of the Academy of Sciences (FIAN). The goal was to create a mineral that could be used in laser systems. The chemical composition of cubic zirconia differs from diamond; it is zirconium dioxide. (Diamond is made of carbon). Abroad it is called jevolite or zirconite.

Artificial diamonds - a threat or an alternative?

There are two main technologies for growing diamond single crystals: HPNT and CVD. The first - HPHT - is based on the use of high temperature and high pressure, the second - CVD - carbon deposition from the gas phase. Both methods are interconnected and complement each other.

The main purpose of artificially grown crystals is to use them in the field of high technology.

China is the main manufacturer and supplier of synthetic diamond powder (grains up to 800 microns in size). The lion's share of the powder—about 80%—is used within China itself. The cost of such powder is 20 cents per unit (previously it was 20 dollars!), It is used mainly for diamond discs in the production of tools.
Larger synthetic diamonds are not yet commercially produced, because... their production is more complex and Chinese scientists are still developing technologies for simultaneously growing a large number of such crystals (and, accordingly, cheaper ones).
Synthetic diamonds do not pose a threat to natural diamonds. This statement is due to the following reasons:

1. Artificial minerals can be more expensive than natural ones or cost slightly less. When there is a leap in the technology of their production, and the price of synthetic ones decreases tenfold, then perhaps the next question will arise - will synthetic ones be used as analogues in the jewelry world and how much demand will this have?
2. The market for synthetic diamonds for jewelry purposes has not yet been formed. There are, of course, lovers of everything technological and prefer materials made by human hands rather than by nature, but there are quite a few of them. Basically, people are willing to pay only for natural gemstones just because they have uniqueness and natural beauty that simply cannot be synthesized by any modern devices.
3. For technical purposes - in tools, medicine, high-tech technologies, diamond powder and crystals have long been used, but natural diamonds are no longer so profitable to use in this market.
4. All artificially grown diamonds that are used for jewelry purposes are, as a rule, promoted under their own brand and no attempt is made to mislead the consumer. Crystals from Swarovski can be as expensive as a cut natural diamond, because its cutting takes up a significant part of the cost.

Artificial yellow diamonds

There are also high-quality gem-quality diamonds grown. They have a rich yellow color, and are 4 times cheaper than natural ones, because they “grow” in 4 days, and not thousands and millions of years. For example, the American company Gemesis specializes in growing diamonds for jewelry purposes. This video is dedicated to this highly technological process.

How to distinguish cubic zirconia from a diamond

The stones most similar to diamonds are cubic zirconias. Diamond and cubic zirconia are used for jewelry purposes and therefore, in practice, the question may arise as to what differences they have. Fraudsters who pass off cubic zirconia as precious stones use the external similarity of minerals that are completely different in chemical and physical composition.
Depending on the heat treatment, it is possible to grow transparent or black cubic zirconia. Colored cubic zirconias are more reminiscent of peridots, white and pink chalcedony, red ruby, alexandrites (with inversion depending on lighting).
The most important difference between cubic zirconia and diamond (except for the chemical composition, of course) is its strength and hardness. It is much softer and therefore can be easily distinguished from a real diamond even at home. So, if you run a stone across a mirror, cubic zirconia will only scratch the surface, while a natural diamond will cut the glass.
You can also distinguish between a natural and an artificial diamond by its brilliance. Even a natural stone that has been used for a long time in jewelry, but becomes dirty from wear, still continues to shine, and cubic zirconia almost loses its shine.
If they want to pass off cubic zirconia as a diamond for fraudulent purposes, then they try to cut it just as difficult, and then with the help of a magnifying glass or microscope you can examine and notice the “split” of the edges. This cannot happen when cutting a natural diamond.
In general, it can be noted that it is quite difficult for a non-specialist to distinguish cubic zirconia if the master sets out to pass it off as a diamond.
Fortunately, this is not accepted in the jewelry world, where cubic zirconia, Swarovski crystals, and other types of artificially created minerals are sold under their own names and are in fairly high demand.

The phrase “Belarusian diamonds” sounds the same to our ears as “Belarusian shrimp.” But don't rush into jokes. Few people know that in the nineties, one of the world’s first diamond synthesis plants was built in Belarus, that the world’s industrial giants are ready to chase Belarusian scientists in this field, and that the quality of crystals was appreciated at the international level.

The world's first synthesized diamond was produced by General Electric back in the 1950s using a special press. The small dirty pebble was no different in properties from natural diamonds. There was only one catch: it needed much more money to synthesize it than to extract it from nature. They gave up on this matter and happily forgot about growing diamonds until the 1980s.

One of the first attempts to produce diamonds using an electric arc furnace. At the end of the 1980s, scientists from the Novosibirsk branch of the Russian Academy of Sciences created a pressless "cut sphere" (BARS) apparatus, with the help of which, for the first time in the world, they obtained a synthesized diamond, ready to compete with natural diamonds not only in quality, but also in cost. For the first synthesized Novosibirsk diamonds, it was significantly lower.

Retired general, seven scientists and $5 million

After successful testing in the 1990s, seven famous Soviet scientists (two of them were Belarusians) got the idea to create the world's first diamond synthesis plant. Due to its good geographical location, Belarus was chosen as the site.

Scientists became the founders of the Adamas company. They took out a loan for 51 million Soviet rubles from Promstroybank of the USSR and began
construction in the village of Atolino, near Minsk.

BARS devices.

The plant was supposed to be quite large: a three-story building, 220 workers. But there was not enough money, so later the founders included the then Belpromstroybank, which provided the company with a line of credit of $5 million, as well as two well-known businessmen in Soviet times, who contributed another $2.5 million.

The investors only managed to complete the building, supply 120 BARS devices and work out the technology a little, when problems began for the founding businessmen - they left the plant without money.

Unexpectedly, four scientists are lured to the United States by retired General Carter Clark. It turns out that in 1995 he bought the technology for producing synthesized diamonds for $60 thousand and founded the Gemesis Diamond company. By the way, everything was formalized, since Russia at that time urgently needed money and was selling off its scientific developments.
The scientists left the Adamas and went to Clark.

One of the largest producers of synthesized diamonds in the world.

Finding themselves in a difficult situation, the founders tried to return the loan
money to the bank, but in vain. In 1999, regarding the management of Adamas
a criminal case was opened. The proceedings lasted for five years, the amount of damage
was estimated at $7 million. Businessmen and a lawyer went abroad. However, four
nevertheless they imprisoned me.

After their release, none of the former Adamas leaders in
Atolino did not return. The remaining three left for St. Petersburg and Moscow
scientists, and with them the technology of diamond synthesis.

The first synthetic diamonds.

This is how three largest centers of synthesized diamonds appeared in the world:
Moscow, St. Petersburg and the American state of Florida. There are a few more small ones
companies, but they say that all the threads lead to the same seven.

What has been happening to the plant itself all this time? It was transferred to balance
Belarusian State University. In one of the parts of the building there was a
enterprise RUE "Adamas BGU": scientists conducted research, studied
production of technical diamonds, improved it. Is it true,
the operation of the installations was very expensive and a financial issue
became more and more acute.

Belarusian diamonds

“When the Chinese, Arabs and Israelis began to persuade us to sell the production, it became clear: there is demand”

On the edge of Atolino stands the same three-story factory building that is so talked about
Soviet scientists dreamed of an ordinary factory with painted walls and
freshly renovated inside. At the checkpoint here there is a policeman and a strict
access mode.

Several years ago, the Adamas BGU enterprise moved into the structure
Office of Presidential Affairs. A little more than a year ago, the vice-rector
The Academy of Management under the President, Maxime Borda, was asked to evaluate
situation in Atolino: does it make sense to set up production there or is it easier
scrap the devices?

— I’ll admit right away: I’m a lawyer by training and the topic is diamond production.
“It was new for me,” Maxim Naumovich leads us into the workshop. - I became
study literature, look at foreign experience. Honestly, I didn’t believe it myself
that our crystals are actually good and can be sold. But
traveled to exhibitions, showed diamonds, cut diamonds, which
grown in our workshop - the experts were delighted with the quality. And when
Armenians, Chinese, Israelis began to call with persuasion to sell
equipment, I finally understood: there are prospects.

So in November 2016, AdamasInvest LLC appeared (previous
The company is now at the stage of liquidation). It also obeys
Presidential Administration and works on a special project
“Restoring the production of synthesized diamonds and developing
jewelry production with inserts from the resulting diamonds.”
45 people work here.

— We received a loan for this project. The money is refundable, there are clear
deadlines,” emphasizes Maxim Naumovich. — We have developed a detailed
business plan, in six months the building was put in order, the workshop was restored and
launched jewelry production. In fact, that’s what we’re doing now
emphasis

According to Maxim Naumovich, it makes sense to go to the industrial diamond market
no: all the players were killed by China. Nine years ago Kyiv
The tool factory sold a sample of a special press to China. China
stamped 40 thousand of them, entered the technical market in 2014
diamonds and collapsed it 20 times. Therefore, even though
Belarusian industrial diamonds are superior in quality to Chinese ones, they cost
they are five times more expensive.

— China is not yet entering the jewelry market. I think they won't let him in
the largest players: US-controlled De Beers and Russian Alrossa.
Therefore, we have good chances in the synthesis of jewelry diamonds,” concludes
Maxim Bord.

Temperature can rise to 2 thousand degrees, pressure - up to 20 thousand atmospheres

A huge hall with dozens of cylinders and a minimum of workers - this is what a workshop with
the same BARS, of which there are 120 here. Service all devices for
a mechanic and an engineer can shift. In total, 10 people work in the workshop.

— They were designed in the 1970s, but in the production of diamonds for jewelry
targets and better than BARS have not yet been found,” shows an open hemisphere
Maxim Naumovich. — In general, there are currently two in the world
diamond production technologies: HTHP (high temperature, high pressure -
high temperature, high pressure) and CVD (chemical vapor deposition -
chemical vapor deposition). The latter is good for
production of industrial diamonds, but not very suitable for jewelry.
The fact is that in a gaseous environment the stone grows in even layers, and in
nature - unevenly, as with HTHP technology, which we
we use.

Maxim Naumovich shows the cylinder control panel. This
special equipment that is controlled manually. At the slightest
Deviations from the set values, workers adjust the indicators.

— It would seem that a computer could monitor how diamonds grow. And
To be honest, I had thoughts of automating this process, -
says the director. “But when I saw our technology, I realized:
there is no point. Firstly, it is expensive, the investment will not pay off. Secondly, growth
diamonds depends on a dozen nuances: for example, temperature changes
in the external environment at various stages. Will a computer be able to take all these into account?
nuances and react like a person? We think not yet.

The BARS themselves are designed quite simply: 3.5 tons of metal, a supply hose
oil, which creates pressure, and contacts, which provide current and temperature.
Inside the device there are two spheres: a large one and a smaller one. Each sphere consists of
six parts - punches made of special alloy
alloy Large ones weigh 16 kilograms, small ones - a little less
kilogram. Small punches are actually a consumable item. They
cost $200 and fail on average after five syntheses.

— Temperature at the entrance to the apparatus — 1500 degrees, pressure — 1800
atmospheres,” explains the director. — The temperature inside can rise to 2
thousand degrees, and pressure - up to 10-20 thousand. Temperature and pressure
change throughout the diamond's growth. This is three days, not
centuries, as in nature.

In the very center of the sphere there is a special porcelain cube. In him,
as Maxim Naumovich says, this is “all science.” Before the cube
sent to BARS, it is “stuffed”: they put in a special compressed
tablet consisting of individual components, usually metals,
here is also a small piece of diamond, which then grows into a large one
stone and graphite rod (graphite is the medium that gives the diamond
opportunity to grow). Then the cube is dried in the oven, soaked
certain materials, and only after all these procedures can it be
lay.

Whether a diamond will grow or not depends even on the warmth of the hands of the workers.

“Production technology is very capricious,” adds Maxim Naumovich.
— A diamond can grow big, maybe small, good or bad, but
it doesn't grow at all. It all depends on a dozen factors: the hands
the engineer who assembles the cube, on how he dries it,
whether it will impregnate correctly - down to the temperature in the workshop and quality
graphite Somehow they also tried to establish production in the Baltic countries.
We purchased equipment, but diamonds did not grow. It turned out that growing a diamond -
It's not just turning on a switch.

After three days, the cube is removed from the BARS, broken and a small
a blank on which the edge of the crystal can be seen. The blank is thrown into
flask and fill with “royal vodka” (three portions of hydrochloric acid and one
nitrogen). The flasks are placed in a special cabinet and heated so that the reaction
went faster.

- Under normal conditions, after two hours the metals dissolve and
“Only the diamond remains,” they say in the laboratory. - Then we extract
diamond, wash it and dip it in the chrome mixture.

This is how the graphite is removed and a pure diamond is obtained. They weigh him
packaged and outsourced to a Russian company for cutting
(there are no free cutting specialists in Belarus, but it’s still time to train new ones
expensive).

— A diamond can lose 30-60% of its original weight. It all depends on
the presence of inclusions and the purity of the stone, they add in production. - Except
In addition, half of all syntheses are guaranteed to produce
high-quality stones for cutting and installation into a product - this is 220
stones per month. In another 20% of cases, the resulting stones are slightly lower
quality.

— It’s enough for work for now, but it’s not enough for development. Here we are fighting
on this task,” Maxim Naumovich shows samples of diamonds. - We
certified our stones at the International Gemological Institute in
Antwerp. The expert opinion is this: our stones are no different from
natural in all their chemical and physical characteristics. Here
exactly the same indicators in terms of strength, lack of reaction to radiation and
etc.

The company mainly grows colorless diamonds weighing up to 1 carat,
getting diamonds of 0.2-0.3 carats. Such stones are mainly used for
earrings and rings. Crystals can also be ennobled: given lemon,
black, red and other colors. But at the enterprise they say that Belarusians
prefer the classics.

“Hindus began to ask to make ritual diamonds from the ashes of the dead”

Having learned about the low prices for Belarusian stones by world standards,
the enterprise was called by Indians with an unusual request: to make ritual
stones.

— They want to preserve the memory of their cremated relatives in
in this form. Compared to a British company that comes close
engaged in similar production, our diamonds were produced five times
cheaper,” explains the director.

— We did not dare to work with the ashes of the dead, but the technology for obtaining
diamonds made from hair were worked out. Yes, diamonds can be obtained from hair. We
We get carbon from them, and then we work according to the same scheme. Technology
We have tested and produced 12 such stones. True, it’s still massive
The implementation of this topic is the next stage of work for us. And in this thread
great potential for science.

But still, the company places its main emphasis on its own jewelry
production. The jewelry workshop, although small (9 people), is
potentially they can produce up to 5 thousand units per month. Last
This week a large batch of Belarusian diamonds arrived in stores.

— Our products are 20-30% cheaper than products with natural
stones, and the synthesized diamonds themselves cost half as much
natural. For example, the selling price for a finished product with a diamond is
0.15 carats is 300 rubles, with a stone of 0.25 carats it will cost
600 rubles,” the director shows samples of products.

These are mostly engagement rings. Maxim Naumovich says that there are plans
there are earrings, cufflinks, silver with diamonds, and even an art series in
ecostyle.

— In Europe, synthesized diamonds are gaining popularity. It is believed that
they are more environmentally friendly than those extracted from the bowels of the earth. And it is true. Especially
that their properties are not inferior to natural ones,” he argues and shares
plans: to gain a foothold in the jewelry market, open a branded store with
prices 40% lower than market prices and much more.

— There is a goal to make our diamonds an affordable Belarusian brand. A
the global task is to further develop scientific research using the profits received
technologies in this area,” adds Maxim Bord.

Diamond, like graphite, is pure carbon in its chemical composition. They are polymorphic modifications of the same element, but their properties differ sharply. This is explained by the difference in their crystal lattices.

Diamond was known in the distant past, is widely used in the present, and there are great prospects for its use in the future. With the development of technology, when the need arose for new types of mineral raw materials, in particular for processing stone, metals, and hard synthetic materials, diamonds acquired a kind of second life. Currently, the existence of the entire manufacturing industry and mechanical engineering (from the creation of powerful units to the manufacture of the finest mechanisms and devices) is practically unthinkable without the use of diamonds. Now diamonds are very widely used as an abrasive material (abrasive powders, pastes, grinding wheels, diamond saws, glass cutters, etc.), which is based primarily on their extremely high hardness. In recent years, other exceptional properties of diamond have increasingly attracted attention: its electrical properties when used as semiconductors, high light refraction in optical devices. Its practical amagnetism is used. Diamond, as a crystalline substance, due to the dense packing of carbon atoms, can become an accumulator and keeper of extensive information.

Diamond density is 3.513 g/cm 3, microhardness 100.6 GPa, elastic modulus 825 GPa, electrical resistivity 10 12 - 10 14 Ohm-cm. In addition to carbon, a diamond crystal always contains a certain amount of impurities, amounting to no more than tenths of a percent. The main chemical elements are impurities in diamond: nitrogen, oxygen, hydrogen, Fe, Ti, Mn, Si, Al.

As is known, the main factors contributing to the formation of diamonds - high pressures and temperatures that occur in the bowels of the earth at great depths.

Artificial diamonds began to be produced in a number of countries in the mid-50s of the 20th century. The introduction of synthetic diamonds eliminated the need to crush most natural diamonds to make powders, pastes and abrasive tools. Synthetic diamonds of the ASO, ASR, ASV, ASC, ACC, SAM, ASB and ASPK brands are produced, as well as micropowders based on synthetic diamonds ASM and ASN with sizes ranging from 1 to 630 nm.

Synthetic diamonds are used mainly for the manufacture of various types of abrasive, blade and drilling tools. The most important areas of application of diamond tools are the processing of tools and machine parts made of metal-ceramic hard alloys, drilling of geological and production wells in hard and abrasive rocks, processing of products made of granite, marble, etc. Powdered synthetic diamonds are most widely used for the manufacture of grinding wheels intended for finishing and sharpening of carbide metal-cutting tools.

There are currently three known methods for synthesizing diamonds:

in the field of thermodynamic stability of diamond, exposing the original carbon-containing material to high static pressure and temperature for a time measured at least several seconds; .

in the field of thermodynamic stability of diamond by exposing the original carbon-containing material to high dynamic pressure and temperature for a time measured in microseconds and fractions of microseconds;

in the region of thermodynamic stability of graphite, carried out at atmospheric and lower pressures and high temperatures by epitaxial growth of diamond on seeds.

The bulk of synthetic diamonds are produced all over the world using the first method, i.e. at high static pressures. A negative feature of the second method is the short-term action of high pressures and temperatures, due to which the newly formed crystals of the new phase are deprived of the possibility of long-term growth and therefore form very small particles.

The third method of obtaining diamonds requires very precise adherence to the process conditions. Otherwise, both diamond and graphite will form on the surface of the seed crystals, and then the graphite will cover the entire surface, and the growth of the diamond phase will stop.

The rational combination of the three conditions necessary for the synthesis of diamonds (temperature, pressure and the presence of a certain environment) underlies the methods for producing synthetic diamonds at high static pressures, used in many countries around the world.

Numerous studies by domestic and foreign scientists in the field of diamond synthesis have made it possible to propose a mechanism for the transformation of graphite into diamond, which is described in detail in various literary sources and is explained by the restructuring of the bond of the electronic configuration sp to sp 3.

As mentioned above, carbon-containing materials are used to synthesize diamonds: glassy carbon, coke, synthetic resins and, of course, graphite. However, you should know that when synthesizing diamonds, the starting material necessarily goes through the graphitization stage. Before heat treatment, the carbon-containing substance must be as homogeneous in chemical composition as possible. In addition, the size distribution of coherent scattering regions (CSRs) should be quite narrow.

It is not advisable to use soot as a starting carbon-containing substance, since it is very finely dispersed. This makes it difficult to stuff the chambers of high-pressure apparatuses.

In practice, certain grades of graphite MPG-6, GM-OZOSCH, MG-OSCh, etc. are used in diamond synthesis technology. In this case, diamonds are formed with a high yield and good quality. The quality of synthesized diamonds is determined by their size and hardness.

Since the synthesis of diamonds occurs at high pressures and temperatures, it is necessary to have reliable devices for solid-phase synthesis, in which high pressures and temperatures can be maintained for a sufficiently long time. You need to be able to measure such pressures and temperatures and determine the degree of their homogeneity in the reaction zone.

Diamond synthesis is carried out in special chambers made of high-strength materials. Such materials are hard alloys based on tungsten carbide and cobalt. The temperature in such devices is raised by passing an electric current through a heating device.

The designs of high-pressure chambers, where temperatures from 727°C to 2227°C are created, are very different. Among the many devices of this kind, we will briefly consider three types of the most common designs: a multi-punch device, a “cylinder-piston” type device and an “anvil with hole” type device.

A representative of the first type is a tetrahedral installation, the diagram of which is shown in Fig. 1.14. The chamber consists of four punches with truncated triangular ends. The ends of these punches have the form of equilateral triangles and limit the tetrahedral volume

Rice. 1.14. Diagram of a tetrahedral high-pressure apparatus; a - arrangement diagram of 4 punches; b- installation in

Assembled, upper punch removed

With the help of four hydraulic presses, symmetrically located in space, the punches move along their axis, forming a working volume. A container of the working substance is placed in it, filled in the form of a tetrahedron.

The working substance is the substance through which pressure is transmitted in all installations where high-temperature testing at high pressures is carried out. It must be a solid with low compressibility and satisfy the following conditions:

have a high melting point and low thermal conductivity;

do not conduct electric current; be chemically inert;

be plastic enough so that it can be used to obtain more or less uniform (quasi-hydrostatic) pressure in a certain volume.

The heater (most often a graphite tube) is filled with the reaction mixture and placed in a tetrahedral container so that the ends of the heater come out from the opposite edges of the tetrahedron. As the punches approach each other, they compress the tetrahedral container. Part of the working substance flows into the gaps between the punches, forming sealing< кладки. Электрический ток для создания нужной температуры подводится нагревателю через пуансоны, соприкасающиеся с нагревательным устрой­ством.

Currently, for the manufacture of containers operating at high pressures and temperatures (10 GPa and 2700°C), mainly four substances are used: talc or steatite 3MgO-4SiOrH 2 O, pyrophyllite Al 2 O 3 -4Si0 2 -H 2 O, lithographic stone 95% CaCO3 + 5% mixture of SiO 2, Al 2 0 3, Fe 2 0 3 and catlinite - red siliceous cemented clay, deposits of which are located in the USA. They differ somewhat in mechanical properties and thermal stability.

Containers can be made either from blocks of appropriate minerals or by pressing powders from these minerals using various binders (liquid glass, bakelite, etc.).

The described tetrahedral chamber requires the application of a pressing device force to it along four axes, which causes considerable difficulties, so chambers are created where compression is carried out by a single piston from some kind of pressing unit. In view of this, devices of the “cylinder - piston” type, the so-called belt devices (belt 1 - belt), have become widespread. The apparatus diagram is shown in Fig. 1.15.