Since scientists learned how to create artificial diamonds, their production has acquired an industrial scale. The status of synthetic crystals has not yet been determined, but jewelry houses have already begun to use artificial diamonds in their products.
At the end of the 18th century, scientists discovered that it is one of the forms of carbon. This marked the beginning of numerous attempts to recreate the gemstone from available materials such as coal or graphite.
How did artificial diamonds come about?
Since the 19th century, many famous physicists and chemists have announced the successful completion of experiments in growing diamonds. True, none of these statements have been documented.
Only in 1927, the Soviet physicist O. Leypunsky made a breakthrough by calculating the conditions necessary for the process. Further research and experiments were carried out in parallel in the USSR, USA and Switzerland.
HPHT and CVD
The first working installation for crystal synthesis was created and patented by the Swede Balthasar Platen. He learned his method from nature.
Natural diamonds are formed at depth, in the hot mantle of the earth's crust with a temperature of more than 1000°C and a pressure of about 50,000 atmospheres.
Platen recreated similar conditions: a cell with nickel, cobalt and iron was heated and pressed with a multi-ton press. In this case, metals acted as a catalyst, and presses simulated pressure of thousands of atmospheres.
This method was called HPHT (High Pressure High Temperature)- high pressure, high temperature. The method is imperfect, but simple and inexpensive. Today it is used for the mass production of industrial diamonds and diamond dust.
In the 60s of the 20th century, a more advanced method was invented CVD (Chemical vapor deposition)- chemical vapor deposition. The essence of the technology is the crystallization of diamonds from hydrocarbon gas onto a substrate grown by the HPHT method. CVD allows for the creation of larger, purer crystals.
In addition to HPHT and CVD, there are other, more narrowly focused technologies:
- detonation synthesis of diamonds- high temperatures and pressures are obtained due to the detonation of graphite. As a result of the decomposition of carbon-containing substances, nanocrystals are formed;
- ultrasonic synthesis of nanodiamonds- allows you to synthesize microcrystals from a suspension of graphite in an organic liquid at normal pressure and room temperature.
Similarities and differences
For a long time, HPHT diamonds and CVD diamonds differed from natural ones in size - under artificial conditions it was impossible to grow a stone larger than a carat. But many companies continue to work to eliminate this shortcoming.
Today, stones with the following characteristics are grown under artificial conditions:
Artificial diamonds have differences from natural ones:
- “artificial” may have metal inclusions left over from production;
- on colored stones you can see growth sectors that appear due to accelerated crystallization processes;
- Natural and artificial crystals luminesce differently in UV rays.
These differences can only be seen with specialized equipment. Therefore, suppliers and sellers of artificial diamonds are required to indicate on the product tags information about the origin of the crystals.
The price per carat depends on the properties of each stone, but in any case, the cost of even the best synthetic diamond will be 2 times lower than a natural one.
Advantages and disadvantages of artificial diamonds:
WHERE SYNTHETIC DIAMONDS ARE USED
High tech
The main areas of application of artificial diamonds are industry and high technology:
- cutting tool- artificial diamonds are among the hardest substances;
- heat conductors- the combination of high thermal conductivity and minimal electrical conductivity makes artificial stone indispensable as a heat sink for high-power lasers and transistors;
- optics - natural diamonds are not suitable for these purposes, as they have too many defects;
Jewelry industry
The technological breakthrough has raised the question of the need for jewelry and diamond mining companies to control the flow of artificial stones into the jewelry market. Now the growth of their sales is limited legally. In addition to this, some companies are opening their own production of artificial jewelry diamonds.
That's exactly what De Beers did. The diamond mining corporation refused to engage in diamond production for a long time. However, in 2018, she created a subsidiary, Lightbox Jewelry, which began selling artificial stones under its own brand.
WHAT ARE ARTIFICIAL DIAMONDS CALLED?
According to the prevailing stereotype, “artificial” is something only externally similar to the original. But imitation does not always mean fake.
Since modern grown diamonds are identical to natural ones, marketers propose replacing the established term “artificial diamond” with wording that would reflect the nature of the origin of this stone more accurately:
- "created";
- “grown in a laboratory”;
- “created in a laboratory.”
Artificially grown "diamonds"
There are other types of artificial stones. They are close in structure to diamonds, but are slightly inferior in terms of hardness characteristics and light refractive indices.
- In nature, it forms small colorless crystals with a diamond luster - silicon carbide. But the natural mineral is extremely rare. Therefore, when we talk about moissanite, we usually talk about artificial carbocorundum. The stone is very similar to diamond (its refractive index is even higher: 2.65 - 2.69), and the hardness is only slightly lower (8.5-9.25 on the Mohs scale). Moissanite is also heat sensitive (it changes color when heated above 65°C).
- Stone is created by combining carbon with other components. It is almost as strong as diamond.
- . Created by scientists from the Physical Institute of the USSR Academy of Sciences (FIAN), after whom it was named. Cubic zirconias are used to imitate diamonds, with which they can easily be confused due to their similar refractive index (2.15-2.25).
When translated into foreign languages, cubic zirconia is often called zircon or zirconium, which is not correct, since it is a mineral with different physical characteristics, and zirconium is a chemical element.
Imitation diamonds
Separately, there are crystals that imitate only the appearance of a diamond. They are significantly inferior in strength and do not have a diamond shine (refractive index is less than 1.9).
- Spinel (degussite). Natural spinel is rare and has a crimson color. Therefore, to imitate diamonds, artificial stones are used, which can be given any color.
- Crystal is high quality glass.
- Swarovski crystals- small stones with perfectly equal edges and various optical effects.
- White sapphire is an artificial colorless sapphire with high strength.
- Rutile - its refractive index is even higher than that of diamond, however, due to the high effect of birefringence, the back edges of the crystal are clouded.
Ever since man appreciated the amazing properties of natural minerals, some of them have become luxury items, others have taken a place in everyday life and rituals. The demand for precious natural stones with small volumes of extraction from the bowels of the earth has made them expensive. Therefore, the issue of creating artificial substitutes that could satisfy demand was actively developed already in previous centuries. A powerful driver of development in this direction was the desire of scammers to sell cheap fakes under the guise of expensive stones.
The origins of man's desire to create stones equivalent to those created by natural forces are found in alchemy. In the 4th century BC. e. alchemists were looking for magical formulas for making artificial gems. But, for example, artificial pearls were found among the ancient archaeological finds of Chinese civilization. Real scientific results were obtained in the middle of the 19th century. Marc Gaudin, a chemist from France, in 1857 showed the world the first unnaturally created stone - ruby. Next came the artificial emerald. Then the production of stones for jewelry began to develop more successfully, and already in the 20th century it was established on a full production scale.
Thus, another secret of nature was revealed to man - he was able to create artificial minerals with his own means. In terms of their composition, artificial substitutes for natural stones are 100% close to natural ones. It is almost impossible for a non-specialist to distinguish natural from artificial. And in some cases, a professional opinion may not be enough without laboratory spectral analysis.
When talking about the differences between natural and artificial stones, we note that the latter have a structure closer to ideal. In natural ones there are often various inclusions, large or smaller cracks on the surface. This is their normal property, but can only serve as a relative sign of natural origin. Such defects may also be present in artificial gems. In addition, cloudy areas and round air bubbles are characteristic only of artificial stones.
The appearance of a large number of artificial stones on the jewelry market has shaken established prices. For some time, it has become much easier to purchase even real rubies, and the cost of natural sapphires and emeralds has decreased. However, very soon after this, jewelers learned to identify artificial stones using optical equipment. Thus the situation was settled again.
Today, almost all precious stones are created in laboratories. Artificial mineral crystals are widely used in electronics and other industries. The production of artificial stones today can be carried out in tons. However, this may not yet be the case with all minerals. Science had to work hardest with diamonds.
The history of the creation of artificial diamond
Isaac Newton suggested that diamond, even though it is the hardest mineral on the planet, undergoes combustion. Since it was known that diamond is created after complex transformations from graphite, which is familiar to us, a hypothesis was put forward about the possibility of the reverse process. Experimental studies of this hypothesis were undertaken by the Florence Academy of Sciences. So it was found that at 1100 degrees Celsius, diamond first turns into graphite and then burns.
In the 30s of the 20th century, Ovsey Leypunsky, as a result of his own research and complex calculations, found out the conditions under which an artificial diamond could be grown. So, the pressure should be more than 4.5 GPa, and the temperature should be 1227 degrees Celsius. In this case, the process must take place in a complex environment - molten metal. Only two decades later, an attempt to create an artificial diamond was crowned with success. But the first diamonds were suitable only for technical purposes. The creation of artificial diamonds requires serious technical means, which makes the process expensive. It was found that artificial and natural diamonds have differences in their attributed magical properties.
Artificial diamonds are closer to the group of quartz minerals; if you put a natural and an artificial diamond next to each other, the latter will fade. The magical properties of artificial minerals are much weaker, so you should be careful when “introducing” a natural stone to an artificial one. Only after a few days of exchanging information at a distance through a partition (made of paper, for example) will the stones be able to “get along” together.
Artificial emeralds
Another expensive pleasure is artificial emeralds. Today, an expensive hydrothermal method is used to create them. For quite a long time, emeralds were produced only in Carol Chatman's laboratory in San Francisco. Today, several companies in the world already use this method and create artificial emeralds.
The fragility of artificial stones is the same as that of natural ones. However, their structure does not (or practically does not) have cracks and other defects inherent in natural stones, therefore laboratory-created emeralds are more durable.
The technology for creating artificial emerald is being improved, but remains very expensive. Therefore, hydrothermal stones are only slightly cheaper than natural ones. They are also resistant to acids, heat, and ultraviolet exposure. The color of artificial emeralds is identical to natural ones.
Cultured pearls - an ancient technology
The Chinese kept the secret of creating artificial pearls for a very long time. But in 1890, the ancient technology finally became known to the Japanese, who put pearl production into industrial production.
The ancient technology of pearl cultivation involves a long process of growing nacre around a small grain of nacre, manually placed first in a piece of fatty tissue of one mollusk, and then in the mantle of another. The process of growing pearls in this way is painstaking, so technologies have been improved and processes have been simplified. This is how the concept of pearl cultivation appeared.
The smallest size of a cultured pearl is the size of a pinhead, and the largest is the size of a pigeon's egg. The shape is of particular importance: round, as close as possible to the ideal, is highly valued. Pearls can also have a teardrop shape and resemble a button. The cost of cultured pearls, and, consequently, products made from them, is lower than that of natural pearls, which makes them more affordable.
As for all artificial gems, you need to remember: these are not fakes, but an attempt by man to replace limited, hard-to-obtain natural resources with creations of science. Therefore, artificial stones occupy a separate and, undoubtedly, worthy place in the jewelry world.
Minerals and minerals tend to end up in the depths of the earth. But people have a need to use various minerals, including diamonds. Therefore, with the development of technology, the development and transition to artificial stone extraction begins. Artificial diamonds are practically no different today from natural minerals. It is difficult even for gemologists to distinguish the stones by appearance, which indicates a high level of similarity.
Artificial diamond
Valuable properties of diamond
Of course, even the development of equipment and technology has not yet caused a complete transition from natural stones to synthetic diamonds. So far, companies growing diamonds in laboratories are guided by the “two out of three” principle:
- quality;
- size;
- profitability.
Two of the three criteria are selected during the process, but until the limit or ideal is reached, scientists have something to strive for.
Most people see rough diamonds in stores already processed as polished diamonds. The stones are set into precious metals and act as expensive jewelry.
The chemical composition of a diamond is carbon with a special crystal lattice structure. The origin of the minerals is not precisely known. There is even a theory of the cosmic origin of diamonds. This is probably why it is difficult to completely repeat or recreate the picture of stone formation in the laboratory.
The first attempts to synthesize the stone began after studying the structure of diamond - it is very dense, the crystal lattice consists of atoms connected by covalent sigma bonds. It is easier to destroy these compounds than to form them.
Despite the fact that the diamond is the number one piece of jewelry, the stone is used in many areas besides jewelry. It was this factor that prompted scientists to synthesize artificial stones. Diamond also has unique characteristics from the point of view of chemistry and physics:
- Highest hardness (10 out of 10 on the Mohs scale). Even the alloy composition of steel is not as hard as diamond.
- The melting point of the substance is 800-1000 degrees Celsius with access to oxygen and up to 4000 degrees Celsius without access of oxygen, with the further transformation of diamond into graphite.
- Diamond is used as a dielectric.
- The mineral has the highest thermal conductivity.
- The stone has luminescence.
- The mineral does not dissolve in acid.
The entry of synthetic diamonds into the market can happen overnight and come as a surprise. The diamond industry will undergo changes and sales volumes will decrease. Semiconductors will begin to be made from stone. Due to their high melting point, diamond semiconductors can be heated to higher temperatures than silicon. At temperatures of about 1000 degrees Celsius, the silicon in the microcircuits begins to melt and shuts down, but the diamond continues to work.
Artificial diamond is a truly useful thing in science and production. There is a common saying among scientists who synthesize diamonds for industry: “If you can’t make anything out of a diamond, make a diamond out of it.”
Methods for creating matter
The first attempts to obtain an artificial diamond began at the end of the 18th century, when the composition of the stone became known, but technology did not make it possible to recreate the required temperature and pressure for the formation of the mineral. It was only in the fifties of the 20th century that attempts to synthesize the substance were successful. Among the diamond-growing countries were the USA, South Africa, and Russia.
Equipment for creating artificial diamonds
The first synthetic diamonds were far from ideal, but today the stones are virtually indistinguishable from natural diamonds. The growing process is labor-intensive and materially expensive. There are several options and forms of diamond synthesis:
- Method for producing HPHT diamonds. This technique is close to natural conditions. With it, it is necessary to maintain a temperature of 1400 degrees Celsius and a pressure of 55,000 atmospheres. The production uses seed diamonds, which are placed on a graphite layer. The size of seed stones is up to 0.5 millimeters in diameter. All components are placed in a special device resembling an autoclave in a certain order. First, a base with a seed is placed, then there is a metal alloy, which is a catalyst, then pressed graphite. Under the influence of temperature and pressure, the covalent pi bonds of graphite are converted into sigma bonds of diamond. The metal melts in the process, and graphite settles on the seed. Synthesis lasts from 4 to 10 days, it all depends on the required size of the stone. The full potential of the technique has not been revealed, and not all scientists trusted this technology until they saw the large gem-quality crystals created. The cut of the resulting stones is the same.
- Synthesis of CVD diamonds. The abbreviation stands for “vapor deposition.” The second name of the procedure is film synthesis. The technology is older and more proven than HPHT production. It is she who creates industrial diamonds that can even be used for blades in microsurgery. The technology also requires a substrate on which a diamond seed is placed and all this is located in special chambers. Vacuum conditions are created in such chambers, after which the space is filled with hydrogen and methane gases. The gases are heated using microwave rays to a temperature of 3000 degrees Celsius, and the carbon that was in the methane settles on the base, which remains cold. Synthetic diamond created using this technology is purer, without nitrogen impurities. This technique has scared most of the concerns that extract stone from nature, since it is capable of producing a clean and large crystal. Such a stone will have virtually no metallic impurities and will be more difficult to distinguish from natural stone. Diamonds obtained using this technology can be used in computers as a semiconductor instead of silicon wafers. But for this it is necessary to improve the growing technique, since the size of the resulting diamonds is currently limited. Today, the parameters of the plates reach the level of 1 centimeter, but in 5 years it is planned to reach the level of 10 centimeters. And the cost of a carat of such a substance will not exceed $5.
- The method of explosive synthesis is one of the latest ideas of scientists that makes it possible to obtain an artificial diamond. The technique makes it possible to obtain artificial stone through the detonation of explosives and subsequent cooling after the explosion. The resulting crystals are small, but the method is close to the natural formation of minerals.
And recently, a direction has emerged that makes it possible to create memorial diamonds. This trend allows the memory of a person to be immortalized in stone. To do this, the body is cremated after death, and graphite is made from the ashes. Next, graphite is used in one of the methods for synthesizing diamonds. So, the stone contains the remains of a human body.
Since all methods are expensive, often in jewelry they use not artificial substances, but fakes or other types of stone. Glass among diamonds is the cheapest and outdated practice. Today it is unsuccessful, since you can easily distinguish the original from the fake - just scratch the stone or look at the play of light. Cubic zirconias are most often sold as diamonds.
Prospects for the development of diamond synthesis
The future of synthetic diamond begins today. The artificial mineral has become a symbol of the times, and soon people will have access to inexpensive and beautiful products. But the technologies are still at the stage of development and improvement. For example, a laboratory in Moscow is capable of growing up to 1 kilogram of diamonds per year using the above technologies. Of course, this is not enough to meet the needs of industry. Further processing of the extracted stones also requires time and equipment.
Therefore, for now, diamond mining is carried out using traditional methods, and no one refuses to develop new deposits or discover kimberlite pipes. As soon as the production of artificial diamonds appeared, the De Beers company - a virtual monopoly on the diamond market - began to worry about its business. The concern's annual turnover is up to $7 billion per year. But so far, synthetic stones are not competitors to natural diamonds, and their market share reaches only 10%.
And, along with synthesis, gemology also developed, which allows us to tell about the origin of the stone. Synthetic diamonds can be easily distinguished from natural ones. The signs are:
- inclusions of metals in stones from the laboratory;
- growth sectors that are identified in colored diamonds;
- different character of diamond luminescence.
Technologies and knowledge of scientists are improving every day. The process has been launched and specialists are working on it. Soon the world will see the results and, perhaps, even abandon the traditional mining of diamonds from the depths of the earth.
On May 26, 2015, the International Gemological Institute (IGI) in Hong Kong issued a certificate for an unusual record diamond weighing 10.02 carats, E color and VS1 clarity. Such precious stones are not so rare in the jewelry world, but the uniqueness of this case was that the stone was not mined from the bowels of the earth, but was cut from a 32-carat synthetic diamond crystal grown by the Russian company New Diamond Technology (NDT). “This is not our first record,” says company general director Nikolai Khikhinashvili. “The previous one, 5-carat, lasted only two months.”
Roman Kolyadin, production director, shows me a small workshop in one of the technology parks near Sestroretsk. The workshop is deserted, only a dozen hydraulic presses line the walls. This is the “deposit” - absolutely flawless diamonds grow inside the presses, under conditions of high temperatures and pressures, micron by micron. The current parameters are reflected on the control panels of the controllers for each press, but Roman asks to shoot the picture so that this data does not get into the frame: “The general principles of diamond synthesis are well known and have been used in industry for more than half a century. But the details of the synthesis modes are one of our company’s know-how.” I pay attention to precision air conditioners that maintain the microclimate in the workshop with an accuracy of tenths of a degree. Is there really a need for such precision? “Remember how we immediately closed the door behind us to avoid a draft? - explains Roman. — Small deviations in temperature conditions can seriously affect the quality of a diamond, and not for the better. And we always strive to achieve perfect quality.”
The process of growing diamond single crystals at high temperature (about 1500 °C, with the desired gradient) and high pressure (50-70 thousand atm.). A hydraulic press compresses a special container, inside of which there is a metal melt (iron, nickel, cobalt, etc.) and graphite. One or more seeds—small diamond crystals—are placed on the substrate. An electric current flows through the chamber, heating the melt to the desired temperature. Under these conditions, the metal serves as a solvent and catalyst for the crystallization of carbon on a seed in the form of diamond. The process of growing one large or several smaller crystals lasts 12-13 days.
Spied in nature
The history of synthetic diamonds begins at the end of the 18th century, when scientists finally realized that this stone is carbon in composition. In the late 19th century, there were attempts to turn cheap versions of carbon (coal or graphite) into a hard and shiny diamond. Claims of successful synthesis were made by many famous scientists, such as the French chemist Henri Moissan or the British physicist William Crookes. Later, however, it was found that none of them actually achieved success, and the first synthetic diamonds were obtained only in 1954 in the laboratories of the General Electric company.
A cheaper process of diamond deposition from an ionized hydrocarbon gas environment on a substrate heated to 600−700°C. Growing single crystals using CVD requires a single crystal diamond substrate grown using HPHT. When deposited on silicon or polycrystalline diamond, a polycrystalline wafer is obtained, which has limited applications in electronics and optics. Growth rate - from 0.1 to 100 µm/hour. The thickness of the plates is usually limited to 2-3 mm, so diamonds cut from it can be used as jewelry, but their size, as a rule, does not exceed 1 carat.
The process used for synthesis at GE was inspired by nature. It is believed that terrestrial diamonds are formed in the mantle, hundreds of kilometers below the Earth's surface, at high temperatures (about 1300 ° C) and high pressure (about 50,000 atm.), and are then brought to the surface by igneous rocks such as kimberlites and lamproites. GE developers used a press to compress a cell containing graphite and an iron-nickel-cobalt melt, which acted as a solvent and catalyst. This process was called HPHT (High Pressure High Temperature - high pressure, high temperature). It was this method that later became commercial for producing inexpensive industrial diamonds and diamond powders (now they are produced in the billions of carats per year), and in the 1970s, with its help, they learned how to make jewelry stones weighing up to 1 carat, although of very average quality.
The two main technologies for the industrial production of synthetic diamonds are HPHT and CVD. There are also a number of exotic methods, such as the synthesis of diamond nanocrystals from graphite during an explosion or an experimental method for producing micron-sized diamonds from a suspension of graphite particles in organic solvents under the influence of ultrasonic cavitation.
Workaround
Since the 1960s, the world has been developing another method of diamond synthesis - CVD (Chemical Vapor Deposition, gas phase deposition). In it, diamonds are deposited onto a heated substrate of hydrocarbon gas, which is ionized using microwave radiation or heated to a high temperature. It was on this synthesis method that in the early 2000s both small startups and large companies like Element Six, part of the De Beers group, began to place great hopes on this method.
Until recently, the HPHT method remained greatly underestimated. “When we bought equipment several years ago, we were all unanimously told that industrial presses were only suitable for the synthesis of diamond powders,” says Nikolai Khikhinashvili. All resources were allocated to the development of CVD, and HPHT technology was considered niche; none of the specialists believed that it could be used to grow sufficiently large crystals. However, according to Nikolai, the company’s specialists managed to develop their own synthesis technology, which literally produced the effect of a bomb exploding in the industry. Several years ago, in a report from one of the gemological laboratories it was written: “The weight of this diamond is 2.30 carats! Until recently, such a size of a diamond was a guarantee of its natural origin.”
Cutting diamonds to create sparkling diamonds is a long process and not very impressive for the uninitiated. Both grown and natural diamonds are processed in exactly the same way.
Girls' best friends
“We, of course, are not the only ones who grow diamonds larger than 5-6 carats,” explains Nikolai. “But all the rest follow the “two out of three” principle: large, high-quality, commercially profitable. We are the first to learn how to obtain large high-quality diamond crystals at an affordable cost. With 32 presses we can produce about 3000 carats per month, and these are very high quality stones - diamonds of D, E, F color and clarity from the purest IF to SI, mainly type II. 80% of our products are jewelry diamonds weighing from 0.5 to 1.5 carats, although we can custom-grow diamonds of any size.” As proof, Nikolai hands me a crystal the size of a 10-ruble coin: “This, for example, is 28 carats. If you cut it, you get a 15-carat diamond.”
In the early 2000s, the global diamond monopolist, De Beers, was very concerned about the impending entry of synthetic diamonds into the jewelry market, fearing that this could undermine its business. But time has shown that there is nothing to be afraid of - synthetic diamonds occupy a very small share of the jewelry market. In addition, during this time, research methods have been developed that make it possible to confidently identify grown diamonds. Signs of synthesis are metal inclusions; growth sectors can be seen in colored diamonds; in addition, HPHT, CVD and natural diamonds have different luminescence patterns in UV rays.
Depending on their nitrogen content, diamonds are classified into one of two main types. Type I diamonds contain up to 0.2% nitrogen, the atoms of which are located at the sites of the crystal lattice in groups (Ia) or singly (Ib). Type I predominates among natural diamonds (98%). As a rule, such stones are rarely colorless. Type IIa diamonds contain virtually no nitrogen (less than 0.001%), making up only 1.8% of natural stones. Even less common (0.2%) are nitrogen-free diamonds with an admixture of boron (IIb). Boron atoms in the crystal lattice sites determine their electrical conductivity and give diamonds a bluish tint.
“How do consumers feel about grown diamonds? It’s good,” says Nikolai, “especially today’s youth. It is important for them that these diamonds are conflict-free and created by people using high technology without interfering with nature. Well, the price is about half as low. Of course, the certificate says that the stones are grown, but they are wearing a diamond ring, not a certificate! And in terms of physical and chemical properties, our diamonds are identical to natural ones.”
So far, most of the profits come from producing diamonds for the jewelry market. However, there is likely to be a huge demand in the coming years for grown diamonds and diamond wafers for specialty optics, microelectronics and other high-tech industrial applications.
From jewelry to industry
Jewelry diamonds are a lucrative part of NDT's business, but tomorrow belongs elsewhere. NDT technical director Alexander Kolyadin likes to say: “If nothing else can be made from a diamond, make a diamond.” In fact, the most promising market for large, high-quality synthetic diamonds is industry. “Not a single natural diamond is suitable for use in special optics or electronics,” says Alexander Kolyadin. - They have too many defects. And the plates cut from our diamonds have an almost perfect crystal lattice. Some research organizations to whom we provide our samples for study can hardly believe the measured parameters - they are so perfect. And not just individual samples - we can confidently ensure repeatability of characteristics, which is vital for industry. Diamonds are heat sinks, they are windows for special optics and for synchrotrons, and, of course, power microelectronics, which are now being developed all over the world.”
“The industrial sector currently accounts for 20% of our production, but in three years we plan to increase it to 50%, especially since demand is growing rapidly. Now we mainly make 4 x 4 and 5 x 5 mm plates, we have cut out a few 7 x 7 and 8 x 8 mm and even 10 x 10 mm plates to order, but this is not mass production yet. Our next goal, says Nikolai Khikhinashvili, is to move on to the production of inch diamond plates. This is the minimum that is in great demand in the mass electronic and optical industry. To obtain such plates, you need to grow a diamond crystal weighing one hundred carats. This is our plan for the near future." “For a decade?” — I clarify. Nikolai looks at me with great surprise: “A decade? We're going to do it before the end of the year."
Diamonds have fascinated people since ancient times, served as luxurious decoration and were evidence of a person’s wealth. Previously, their value was determined by the fact that they were only of natural origin, were rare, and their extraction was an extremely difficult task. Now a worthy and inexpensive alternative has appeared - artificially grown diamonds.
Historical information
For the first time, artificial diamond became known thanks to space, and more specifically, a meteorite that fell from the sky. This happened at the beginning of the last century in France, after which the French researcher Henri Moissan discovered a stone very similar in properties to diamond in the crater formed after the fall. Subsequently, Moissan was awarded the Nobel Prize for his discovery, and the stone he discovered was named in his honor - moissanite.
Moissanite In Sweden in 1950, local scientists first grew a gemstone in the laboratory. Soviet scientists also distinguished themselves in the creation of artificially grown diamonds. In 1976, based on carbon compounds, they managed to create an analogue called cubic zirconia.
Types of artificial diamonds
There are two main types of artificial diamonds: with a natural structure (cubic zirconia, moissanite) and the so-called. “Substitutes” - crystals, polymers, rutiles. Each of the above representatives of the synthetic diamond market has its own characteristics:
- Cubic zirconias come in various colors and cast glare well. Colorless specimens are considered the most valuable. They differ from natural diamonds in weight: as a rule, cubic zirconia is a little heavier. The disadvantages of the stone include its ability to quickly become cloudy, and it is also scratched.
- Moissanites are among the most valuable synthetic diamonds. The stone gained its reputation due to its strength, smoothness and bright shine. It differs from natural diamond due to its excessively strong reflections.
- Rhinestones are an imitation of precious stone, which is widely used for the design of clothing, accessories, manicure, etc. They are created from glass or acrylic. The most popular manufacturer of rhinestones is the Austrian company Swarovski. The products of this brand are in demand all over the world due to their wide range, affordable prices and good quality.
Rhinestones In the CIS, the largest diamond mining enterprise is the ALROSA group of companies. For a long time, Andrey Zharkov was the manager of ALROSA. At the moment, Zharkov no longer heads the company, as he has opened his own enterprise for the production of synthetic diamonds. As Andrey Zharkov admits, he considers synthetic diamonds to be “diamonds of the new century” and is confident that the synthetic diamond market has a great future.
Methods for growing artificial stones
There are many known methods for creating synthetic diamonds. Diamond is the hardest stone on earth, so the developers of its analogues try to ensure that their products are not inferior to the standard. For this purpose, huge complexes are built in which certain conditions are met and the latest equipment is used. It is worth noting that the price of some artificial diamonds exceeds the cost of natural ones, since the manufacturer incurs enormous costs in their production.
Growing Diamonds Below are the most common methods for growing artificial diamonds:
- The laboratory creates conditions as close as possible to those in which diamonds are formed in nature. A high pressure press is used for this. There is a special compartment inside the body of this press. Graphite is placed in a compartment in a special capsule, which under pressure turns into diamond. Electricity is supplied to the capsule. First, it is cooled, then it is compressed by a press and an electrical impulse is applied. The ice is then defrosted and the finished diamond is removed from the capsule. The diamonds obtained in this way are cloudy and porous, and are used more for industrial purposes.
- Growing stone in a methane environment. Additional mass is added to the natural diamond, which is used as a “seed” material. The diamond is heated to a temperature of 1111 degrees. It is impossible to raise the temperature higher, because at 1200 degrees the stone begins to turn into graphite. Carbon atoms are added to the hot diamond in the capsule. Under such conditions, approximately 0.2% of carbon from the total mass of the seed diamond grows in 1 hour.
- Explosion method. Used to produce diamond dust. Graphite is placed on a special heated surface, which becomes diamond dust during a detonation wave.
- Application of catalysts. Metals such as iron, rhodium, palladium, and platinum are used as catalysts. Catalyst metals make the diamond production process easier because less pressure is required and the temperature is not as high. The crystals themselves are obtained in the space between hot graphite and the film of the metal catalyst. Diamonds obtained by this method are used mainly for industrial purposes.
Cost of artificial diamonds
The pricing of synthetic diamonds depends on many factors. These include the complexity of production, color, cut, etc. Particular attention should be paid to current trends in the precious stones market. Depending on fashion trends, rutiles, cubic zirconia, and moissonites were in demand at different times. People whose interest in stones is driven not so much by aesthetic needs as by financial ones invest in the production of synthetic diamonds.
For example, some moissonite specimens are more expensive than real diamonds. It's all about production technology and cutting of the stone. In the United States, the price of moissonite ranges from $70 to $150 per carat. Cubic zirconia is much cheaper: its cost ranges from 1 to 5 dollars. The price of artificial diamonds also depends on the color. It is extremely difficult to achieve crystal transparency of a stone; for this reason, an analog stone of pure water will cost more than the same yellow or reddish specimen.
Today, most of the jewelry presented in jewelry stores is made using synthetic diamonds with the mass market market in mind. The ratio of homemade diamonds to natural stones is approximately 3:1. As a rule, these are cubic zirconias set in white and yellow gold, silver, and platinum. Unlike natural ones, artificial diamonds can be worn at any time of the day, while their “natural” counterpart is intended primarily for evening wear.
For everyday wear, earrings made of gold or silver with small crystals are suitable. It looks simple and tasteful at the same time.
Bracelets and rings with iridescent stones are worn mainly when going out, but a ring with a modest cubic zirconia in a white gold frame is quite suitable for everyday work.
To extend the life of jewelry with homemade stones, you should properly care for them. Before cleaning or contact with aggressive detergents, you must remove all rings and bracelets from your hands. Items containing artificially grown diamonds should be regularly wiped with a handkerchief made of soft fabric, and they should be stored in a box in an individual box or fabric bag. It is also advisable to choose a box made of stone (malachite, marble), since wood with its fumes can harm the stones, making them dull.
Advantages and disadvantages
Undoubtedly, the advent of man-made diamonds is progress both for the gemstone market and for ordinary people. Previously, few people could afford jewelry with diamonds due to their fabulous cost. Today, the market for synthetic diamonds is replete with rhinestones and cubic zirconia, and wearing such a “fake” is not at all shameful. On the contrary, many celebrities openly admit that they prefer jewelry.
Still, despite such a big advantage, synthetic diamonds also have their disadvantages. The most basic one is a yellow haze, which is visible under a microscope on any copy of such a diamond. The reason for its appearance is that during the production of stones a certain amount of nitrogen is released, which acquires a yellow tint and remains interspersed in the artificial diamond. From this haze, an experienced jeweler can easily determine the origin of the stone.
Another disadvantage of synthetic stones is that some of them do not have the same degree of hardness as their real counterpart, which is why they are easily scratched and become dull. Moissanite, for example, is almost the same in hardness as a real stone, but it glares too brightly in the light, which also repels some lovers of discreet beauty.
