Production of artificial diamond equipment. How do they get and where does artificial diamonds use? Artificial and fake

1.15. Belt type apparatus diagram: 1 - - Punson, 2 - - Container

Fig. 1.16. High Pressure Camera Scheme with Supporting Rings (Ovil with Lunka): 1 -Puanson, 2 - - Steel Ring, 3 - Container, 4 - Sample, 5 - Clearance

The main parts of it are two conical punchson (1) from a solid alloy, which in several layers are steel bandages. Their ends come into a hollow cylinder from a solid alloy, also a strengthened bandage set. The cylindrical container from the working substance (2) is placed inside the cylinder (2), in which the heater with the reaction mixture is located. The heater is a tube of electrically conductive material, the heater axis coincides with the axis of the container.

All installation is placed in the hydraulic press. When shifting the punches, the working substance is plastically deformed, part it counts into the gaps between the cylinder and the punch and reliably locks the compression chamber. Thanks to the formulated gaskets from the working substance, the punches are electrically isolated from the cylinder.

Heating is carried out by passing the electric current through the heater coming into contact with the punches to which the electrocontacts from the current source are connected.

In the installation of type "BelT" it is possible to obtain pressure of about 20 GPa and temperatures of about 2700 ° C and you can have a large reaction volume. However, the details of this design are very complex in manufacturing, and its operation requires high personnel qualifications. Therefore, the USSR has developed a more simple design of the "anvil with a hole", which has been widely distributed not only in laboratory studies, but also in industry.

In fig. 1.16 shows the scheme of the described apparatus in the context. The device includes two identical punchs from solid alloy (1), each of which in the end has a central recess (well) in the form of a segment of a sphere, surrounded by a surface treated on the cone. On the side surface, each punch (1) is bonded by a steel ring (3). A container (2) made from the corresponding working substance is placed between the end surfaces of the punches. The sample (4) is collected together with the heating element and is inserted into the cavity of the container. The digit (5) is marked between the cone treated on the cone, the peripheral areas of the surface of the punches.

High pressure (up to 7 GPa) and temperature (up to 2200 ° C) are obtained as follows. The sample (carbon-containing material) together with the heating element (4) is placed in the container (2), which assembled is installed in the high pressure chamber formed by the friend To the other ends of Punns (1). The camera assembly is laid in the hydraulic press. Under the repellent punches, the peripheral part of the container (2) is gradually deformed and fills the gap (5). The plastic flow of the container material (2) is terminated when, with an increase in the compressive force of the press, the required pressure in the chamber is achieved. The electrical power required to heat the sample. (4). Fixed on, heater through punches (1), for which one of the punches should be electrically isolated from the rest of the equipment.

In this case, the carbide part has a lens-shaped deepening and is called "anvil with a hole" (NL), and the container resembles a form of lentil. To create higher pressure, the NL camera has been changed. On the conical surface of Punson, ring grooves were made in the form of a large torque diameter (Fig. 1.17).

This does not affect the principle of operation of the chambers, but significantly increases the durability of the carbide part to the destruction. In such devices, pressures at 13-14 GPa can be achieved. The design received the name "anvil with a hole and toroid (NLT)", and the container for it is "toroid" (Fig. 1.18).

Fig. 1.17. High IC 1.18 camera circuit. Axial section of a toroid type toroid type toroid type container

An important circumstance that strongly affects the nature of the synthesis of diamonds in high-pressure chambers with a solid medium is the occurrence of temperature gradients and pressure in the reaction zone, which complicates the process technology. The true temperature value can be determined directly in the thermocouple synthesis chamber. In the temperature range up to 930 ° C, platinum-plating and for higher temperatures - tungsten-rhenium thermocouples are used.

The direct synthesis of diamonds from carbon-containing substances without the addition of any contributing to the formation of diamonds of substances (catalysts, solvents) occurs at very high pressures and temperatures. When catalytic synthesis, it is possible to reduce the temperature and pressure more than 2 times (4.1 - 4.5 GPa, 1150-1200 ° C), so the catalytic synthesis of diamonds is now the main one. Catalysts are: manganese, chrome, tantalum, as well as alloys formed by these elements with metals, which are catalytically inactive for this process. In addition, diamond synthesis catalysts are alloys of Ti, Zr, HF, V, W, MO, NB transition elements with metals, AG, AI. The conversion of graphite in the diamond occurs with good contact between it and the liquid (melted) metal.

It should be noted that in synthetic diamonds obtained by catalysts, various inclusions are always observed.

It is impossible not to say about the possibility of obtaining a diamond from the gas phase at low pressures, i.e. On the so-called epitaxial synthesis of matter.

Along with obtaining a diamond under conditions when it is a thermodynamically stable substance (at high pressures), diamonds can be synthesized in the region of its instability, i.e. With relatively low pressures. For this, they carry out thermal decomposition of carbon-based foxhas of gaseous substances, such as methane, acetylene, carbon monoxide, etc. The diamond crystals are first introduced into the reaction vessel. If there is a line of a diamond crystal, near which the concentration of carbon atoms in the form of steam exceeds the corresponding equilibrium, then the excess carbon atoms will be deposited on this face, reproducing the crystal structure of the diamond grid. This process is very slow. In addition, working conditions favors education on the surface of a graphite substrate to periodically delete it from it. The specific productivity of such installations is small, and the process itself has not yet found industrial applications.

In the field of thermodynamic stability of the diamond, it can be obtained in the form of diamond dust from carbon-containing substances in an explosive wave. This synthesis option should be attributed to the method of dynamic immersion.

Minerals and minerals have property to end in the depths of the Earth. But people have the need to use various minerals, including diamonds. Therefore, the development of technologies begin to develop and transition to artificial mining stones. Artificial diamonds practically do not differ today from natural minerals. By type, stones are difficult to distinguish even hemologists, which indicates a high level of similarity.

Artificial diamond

Valuable properties of Almaz.

Of course, even the development of equipment and technologies has not yet caused a complete transition from natural stones on synthetic diamonds. While companies in laboratories are guided by the principle of "two of three":

• quality;
• the size;
• profitability.

Two of the three criteria are chosen in the process, but for now the limit or ideal is not achieved, there is a scientist to strive for.

Most people see diamonds in the treated form as diamonds. Stones will be sent to precious metals and act as expensive jewelry.

For chemical composition, the diamond is carbon with a special structure of the crystal lattice. The origin of minerals is not exactly known. There is even the theory of Space origin of diamonds. Probably, therefore, it is difficult to completely repeat or recreate the picture of the formation of stone in the laboratory.

The first attempts to synthesize the stone began after the study of the diamond structure - it is very dense, the crystal lattice consists of atoms connected by covalent sigma-stones. Destroy these connections are easier than to form them.

Despite the fact that the diamond is an ornament number one, the stone is used in many areas, in addition to the jewelry. It is this factor that came across scientists on synthesis of artificial stones. And the diamond has unique characteristics from the point of view of chemistry and physics:

• The highest hardness (10 of 10 on the Moos scale). Even the composition of the alloy has become not so solid as the diamond.
• The melting point of the substance is 800-1000 degrees Celsius with oxygen access and up to 4000 degrees Celsius without access of oxygen, with further conversion of diamond to graphite.
• Diamond is used as a dielectric.
• The mineral has the highest thermal conductivity.
• The stone has a luminescence.
• Mineral does not dissolve in acid.

Exit to the market of synthetic diamonds can happen at one point and become a surprise. The diamond industry will undergo changes, sales will decrease. From the stone will begin to make semiconductors. Due to the high melting point, the semiconductors from the diamond can be warmed up to large indicators than silicon. At temperatures about 1000 degrees Celsius silicon in chips begins to melt and turns off, and the diamond continues to work.

Artificial diamond is a really useful thing in science and production. Among scientists who are engaged in the synthesis of diamonds for industry, such a saying is common: "If nothing can be made from the diamond, make a diamond out of it."

Methods of creating a substance

The first attempts to get diamond artificial began at the end of the 18th century, when it became known about the composition of the stone, but technology did not allow to recreate the desired temperature and pressure for the formation of a mineral. Only in the fifties of the XX century, the synthesis attempts were crowned with success. Among the countries growing diamonds were the United States, South Africa, Russia.

Equipment for creating artificial diamonds

The first synthetic diamonds were far from ideal, but today the stones are almost indistinguishable from natural diamonds. The process of cultivation is time consuming and financially expensive. There are several variants and forms of diamond synthesis:

• The method of obtaining HPHT diamonds. This technique is close to natural conditions. With it, it is necessary to observe the temperature of 1400 degrees Celsius and a pressure of 55,000 atmospheres. The production uses seed diamonds that are put on the formation of graphite. Size of seed stones up to 0.5 millimeters in diameter. All components are placed in a special device resembling an autoclave in a certain order. At first there is a base with seed, then a metal alloy is located, which is a catalyst, then pressed graphite. Under the influence of temperature and pressure, covalent pi-links of graphite are converted into diamond sigma. Metal in the process melts, and graphite settles on the seed. Synthesis lasts from 4 to 10 days, it all depends on the required sizes of the stone. The entire potential of the methodology is not disclosed, and not all scientists trusted this technology until the created major jewelry crystals have seen. The cut from the resulting stones is the same.
• Synthesis CVD diamonds. The abbreviation is decrypted as "vapor deposition." The second name of the procedure is a film synthesis. Technology older and tested than HPHT production. It is she who creates industrial diamonds that can be used even for blades in microsurgery. The technology also needs a substrate to which the diamond seed is placed and all this is located in special chambers. In such cameras, vacuum conditions are created, after which the space is filled with hydrogen and methane gases. Gases are warmed up with the help of microwave rays to a temperature of 3000 degrees Celsius, and carbon, which was in methane, settles the basis that remains cold. The synthetic diamond created by this technology is cleaner, without nitrogen impurities. This technique frightened most concerns producing stone in nature, because it is capable of giveing \u200b\u200ba clean and large crystal. Such a stone practically will not have metal impurities and it will be more difficult to distinguish from natural. Diamonds obtained by this technology can be used in computers as a semiconductor instead of silicon plates. But for this it is necessary to improve the cultivation technique, since the dimensions of the obtained diamonds are limited. Today, the parameters of the plates reach 1 centimeter, but after 5 years it is planned to achieve a plank of 10 centimeters. And the cost of carats of such a substance will not exceed 5 dollars.
• The way of explosive synthesis is one of the last ideas of scientists who allow to obtain an artificial diamond. The technique makes it possible to obtain an artificial stone due to the detonation of explosives and the subsequent cooling after the explosion. Crystals resulting in small, but the method is close to the natural formation of minerals.

And recently, a direction arose to create memorial diamonds. This trend allows you to perpetuate the memory of a person in stone. For this, the body after death can be cremation, and graphite is manufactured from the dust. Next, graphite is used in one of the methods of diamond synthesis. So, the stone contains the remains of the human body.

Since all the ways are expensive, often in jewelry uses not artificial substances, and fakes or other varieties of stone. Glass among diamonds is the cheapest and outdated practice. Today it is unsuccessful, because to recognize the original from the fake can be easily - it is enough to scratch a stone or look at the game of light. Most often, fianits sell as diamonds.

The prospect of the development of diamond synthesis

The future of the synthetic diamond begins today. Artificial mineral became a symbol of time, and soon people will have access to inexpensive and beautiful products. But while technology is under development and improvement. For example, the laboratory in Moscow is capable of grown on the above technologies to 1 kilogram of diamonds per year. Of course, this is not enough to ensure the needs of industry. Further processing of mined stones also require time and equipment.

Therefore, it is still carried out in traditional ways, and no one refuses to develop new deposits, the discovery of kimberlite tubes. As soon as the production of artificial diamonds appeared, De Beers - almost a monopoly on the diamond market - began to worry about his business. The concern's annual turnover is up to 7 billion dollars a year. But while synthetic stones are not competitors in natural diamonds, and their market share reaches only 10%.

And also, along with synthesis, hemology developed, which allows you to talk about the origin of the stone. Synthetic diamonds can be easily distinguished from natural. As signs allocate:

• inclusion of metals in stones from the laboratory;
• growth sectors, which are defined in color diamonds;
• different character luminescence diamonds.

Technology and knowledge of scientists are improving every day. The process is launched, specialists work on it. Soon the world will see the results and may even give up the traditional mining of diamonds from the depths of the Earth.

Many scientists have sought to grow an artificial diamond, since the theory has arisen that it is possible. Nowadays, the business for creating synthetic stones is very popular, as this is the only opportunity to meet the need for this mineral. In nature, it is found very imperfect, and its use in industry and electronics is unprofitable. But, thanks to the work of the great minds of the world, the decision was found in the face of laboratory crystals. About them and will be discussed.

Laboratory crystals: fake or full replacement

Call synthetic diamonds - incorrectly. Rather, it is the same mineral produced by different paths. It is worth noting that the only differences between them is the method of appearance. In one case, the stones are born in nature, in the other, the man is applied to their creation.

Artificial stone produced in the laboratory, acquires all the properties of the "real" stone:

• strength;
• structure;
• shine;
• refractive factor;
• specific gravity;
• thermal conductivity;
• resistance.

But there is one difference of artificial diamonds - the complete absence of defects. This makes them perfect material for industrial and jewelry purposes.

It is curious that only 20% of the diamonds mined in nature can be used to create jewelry. The rest of the stones have microcracks, inclusions and clouds. When using high-quality technologies, distinguish the natural mineral from artificially difficult, even if there are laboratory equipment.

Alternative names in science and common

In the scientific world, synthetic diamonds are called the technology with which their production is associated. There are HPHT diamonds, which means - created under high pressure and temperature. And CDV-diamonds are decoded as chemical precipitation from steam. We will tell you about the technologies themselves next.

But artificial diamonds are not always a full copy. There are such species like fianit, mobsanite, rhinestone, ferroelectric, rutile, blocking and cerussite. Zirconium dioxide is the most common "fake," having nothing to do with a real diamond.

Do not know people call artificial diamond fianit that is a big mistake. Of course, it perfectly imitates a diamond, thanks to the strength and refraction. Some experts cannot "face" to distinguish it from the original stone. Therefore, they are widely used in the jewelry industry.

Travel into the past

Let's talk about how much years have passed since the appearance of the hypothesis that it is possible to obtain synthetic diamonds. For the first time, they spoke about it in 1797, finding out that the stone completely consists of carbon. But, it was possible to realize the idea only in 1926, but it cannot be called a complete success. The resulting sample was far from the original, but became the starting point in the studies.

Only in 1941, General Electrics became interested in technology. Their plan was to heat carbon to 3000 degrees under a pressure of 5 GPa. But production had to stop due to the 2nd World War. Return to studies managed 10 years later.

High-quality diamond artificial origin, suitable for mass production, managed only in 1954. But, his sizes were so small that it was impossible to use it in the jewelry industry. Their business has spread to industry. It was possible to solve the problem in 1970, but then the stones did not reach more than 1 carat.

Today, everything has changed and in laboratories can grow really big stones. The maximum size of an artificial diamond listed in the Guinness Book of Records is 34 carats.

Color gamut of laboratory stones

Many people are interested in which shades are taking diamonds grown in the laboratory. To date, scientists manage to "paint" synthetic pebbles in two colors: yellow and blue. But, colorless diamonds are most popular, although more time and effort are required to create them.

Getting transparent artificial diamonds are difficult because it is necessary to constantly monitor the boron or nitrogen in the composition. To the stones created by such efforts, even small samples in 1 carat are most accurate and appreciated.

Blue synthetic diamonds are obtained by mixing to carbon bromine. Their shades are different: from dense blue to pale blue. For yellow diamonds use nitrogen. Then, the color is obtained from the acid-lemon to the flame-orange. Nickel is needed to get black stones in the laboratory.

Application and opening areas

About 80% of the diamonds created are used in industry and other areas of human life. For example, the production of bearings, tips for drills. From small pebbles, you can make a diamond crumb and powder used for spraying knives or grinding tools.

The synthetic diamond plays a major role in electronics. Of these, they create needles, interlayers in chips and counters to keep thermal conductivity and resistance. And this is only an approximate sales market, where you can sell high-quality artificial stones.

For the production of diamonds grown by the CVD method, the most important role is high-tech spheres. They are needed to create mobile phones. They are used in the reproduction of laser rays used in medicine: with their help, a variety of fatal diseases are treated. Therefore, the role of synthetic stones is enormous.

Technologies that have passed inspection and system of the future

Tell how to grow a diamond in laboratory conditions. Modern plant for their manufacture, uses two technologies. The first in popularity and occurrence - HPHT. It is based on the heating of carbon under high pressure. Its main advantage is the relatively low cost of the resulting stones.

How diamonds according to the CVD methodology can be understood if you submit a gas chamber. Inside there is a hydrocarbon gas heaped to a silicon plate by heating or using microwave radiation. As a result of the reaction, a plate was obtained in 2-3 mm thick. Therefore, its main branch of application is optics and electronics.

In some laboratories growing synthetic stones, the explosive technology of diamond crumb is distributed. It is based on the fact that the explosion creates high pressure and there is a lot of heat. The main thing is to quickly lower the camera into the water so as not to give a diamond to switch to the graphite state.

The problem of "explosive technique" is that the precious baby is inside the graphite. It must be flush by boiling in nitric acid throughout the day, at a temperature of 250 degrees.

Beautiful death: new technology for obtaining jewels

In 1999, scientists have learned how to get a diamond from the dust of a person or an animal. After 3 years, the technology was widely publicized and the creation of diamonds from the remains turned into a profitable business. The technique does not stand still. Earlier for the production of stone, I needed all ashes from cremation, but today there is enough hair curl.

When a person cremates, very high temperatures are required. Thanks to this, it appeared the opportunity to save close in the jewelry. But, the price of such burial is not small: 5000-22000 dollars.

Attention! Prices indicated on the site are not a public offer, and the administration is not responsible for them.

Get a stone from the dust of loved ones, it is possible for 12-14 weeks, depending on the complexity of the order. The size of such diamonds is from 0.25 to 2 carats. The price varies depending on the color and size. To create one carat of yellow diamond, 100 g of duct or 35-40 g of hair and $ 6250 will be required. For the cultivation of a blue mineral, 500 g of ash or 100 g of hair is spent. Its price begins from $ 11750 per carat.

Financial Side Question

And now I will estimate how much diamond jewelry from artificial diamonds will cost. Many underestimate the importance of these stones, and meanwhile their price is sometimes higher than natural analogues. There are several reasons:

• visually they are indistinguishable;
• they have no inclusions, which is called "Pure Water Stone";
• they are stronger because they do not have cracks;
• their color will not fade;
• they are less speculative.

The cost of stones depends on their mass, the quality of the cut and the methodology of creation. The most common zirconium dioxide (the most famous name is fianit), it costs only $ 1.5-6 for carat. But the value of the Moissanite ranges from 75 to 155 dollars.

Comparative characteristics

Before starting the planning of own business on the cultivation of artificial diamond, it is important to understand that the synthetic mineral and natural stone is exactly the same. We will collect together all the most important properties for the consumer and compare them.

Analysis data is shown in the table:

The authenticity of diamonds usually recognize these experts who have special hemologies and specialized equipment. Therefore, the self-definition of the authenticity of diamonds may be too expensive, as it is easy to make an error.

Artificial diamonds include artificial topaz and spinel, rutic, zircon, leukosapphyr. If you comply with some recommendations and additional precautions when buying diamonds, you can reduce the risks of acquiring a fake.

• Cutton diamond

On the jewelry market there are rules when diamonds can be called those diamonds that have fifty-seven faces. Since thanks to such a shape of the cut, the entire falling light on the crystal can be reflected.

If the stone has a different type of treatment, such as "Marquis", "Pear", "Princess", "Emerald", then in this case it will correctly call it a diamond, not a diamond. Therefore, it is often possible to notice on jewelry labels. The inscription in which it is beloved that the decoration with diamonds and diamonds.

When assessing the quality of stones, an alphabetic designation is applied (A, B, B, G). So, the letter "A" means that the cut is very good. "B" means "good", "B" refers to the average degree and "g" indicates a poor processing of the crystal.

The diamonds that belong to the group "A" are distinguished by such light effect, where the luminous flux is entirely displayed by the rear edges of the crystal, as if from the mirrors. And there is a diamond to bring the crown to the light, as the only shining point will be visible.

• Decoding a shortcut

For example, the label is the following entry: Diamond 2 kr 57-010 4/2. For a unrealized buyer, this does not mean anything. Let's try to figure out. The number "2" means that two diamonds are inlaid in the product. "CR" indicates that the round shape of the cut is applied. "57" - corresponds to the number of faces in the cut. "0.10" - indicates the total weight of diamonds in carats (one carat is 0.2 g, and in the circumference is 6.55 mm).

"4" means the color code of a diamond. An estimated color scale of crystals whose weight exceeds 0.30 carats, divided by nine sections. Absolutely colorless stones are denoted by the number "1", and the yellowish marked the number "9".

"2" is considered an indicator of defectiveness, crystals whose weight exceeds 0.30 carats, is divided into twelve parts. The numbers from "1" to "3" correspond to the stones without inclusions, from "4" to "6" denote stones with impurities that are not visible to the naked eye. Crystals in which you can barely distinguish inclusions are attributed to the section from "7" to "12". The number "12" is the indicator that the stone is completely filled with inclusions.

• Methods of primary surveys to determine the authenticity of the diamond

From other colorless crystals, diamonds can be distinguished using some primary survey methods. It is known that all the rhinestones of good quality are soft stones, and therefore can be eager, and diamonds are considered the most durable and are not affected by damage.

Therefore, during an inspection of an instance through a magnifying glass, you can notice scratches and scratching (especially on edges). Although it is worth remembering that diamonds that were not stored in a special box with nests may have some defects.

Another simple method for determining the authenticity of the gemstone can be considered an external examination of the jewelry frame. Starting from 1800, the rims for diamonds are made open, and rhinestones are placed in closed rims. Therefore, you can turn the sample and see if the lower part of the crystal is noticeable.

Diamonds have a crystal lattice with one refractive index. If, when inspecting the rear edges of the stone through a pocket magnifying glass (if you send it from above), it will noticeably duplicate the faces, it will talk about the fake of the stone.

Some diamond simulation, for example, zircon (cubically stable), when inspection through a magnifying glass, will have edges of the edges not so sharp, like the original, as if they are cast in shape. But, without a certain experience, such a difference is difficult to notice.

It is possible to determine the fake on the following method: it is necessary to lower the stone into hydrochloric acid, as a result of which the artificial sample is like, and the original will not suffer from it.

Also, you can determine the authenticity of the hardness of the diamond. So it can leave scratches on glass and polished surfaces. You can lose the stone to sandpaper, then immediately imitation will be clear before you or not, as traces from it will remain on artificial samples.

It is recommended another way to identify real diamonds. To do this, it is necessary to put a stone into water with glycerin. Synthetic samples will not be noticeable in such a solution, while the diamond will shine brightly.

To determine the authenticity of a diamond, a special fluid can also be used with a density of 3.52. In such a solution, imitation is usually drowning or pop up. While the diamond will be in a "suspended" condition.

• Natural crystals used for diamond imitation

Artificial diamonds are usually made from natural origin stones. These include: white zircon, quartz (rhinestone), white beryl, white topaz, white sapphire.

• Artificial stones that are used for diamond imitation

In addition to natural crystals, diamonds are made of artificial stones, which include: Moissanite, Spinel, Niobat Lithium, Cubic Stabilized Zircon (KSS), as well as Titanite Stronting GHG (Granat, Gallium, Gadolinium).

Among the above-listed artificial materials of Moissanite, it is considered a relatively new stone, which perfectly imitates not large diamonds. It has a double refractive factor, as well as in Moassat, characteristic tubular impurities come across.

If you check this material on a reflectometer or thermal measure, it will be difficult to determine the fake.

In recent decades, technologies of artificial cultivation of precious stones and their analogues are actively developing. Of course, most of the manufacturers, and jewelers, and buyers are interested in the possibility of producing the king of precious stones - diamond, which is due to its price. The high price of natural diamonds is connected, first of all, with their properties, such as phenomenal hardness, the magnificent ability to refract and return the light that ensures the sparkling and the game of the faceted diamond. But there is another important factor - a significant monopolization and closure of the diamond production market, which does not allow prices for stones to fall according to the natural market laws of competition.

Recently, the laboratory has developed several technologies for growing synthetic diamond, two of them are most common:

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

Produced artificial diamonds have a number of shortcomings:

1. The main drawback is color. It is fairly easy to synthesize a saturated color stone (yellow, blue, green, pink, etc.), but still remains an unresolved task of production of perfectly colorless diamonds. A standard artificial diamond has an I-K color on the GIA scale, which corresponds to the color of 6-7 on the Russian standard of the TU. This means that the synthetic diamond has a well-distinguishable yellowish tint. The latest achievements in HPHT and CVD technologies allowed to obtain a G-H color, i.e. 4-5 Color for TU, but the complexity of production does not yet allow prices for such stones to drop significantly lower prices for natural diamonds of similar characteristics.
2. Foreign ones, metal for HPHT and black threads of incredited carbon for CVD.
3. The presence of metal impurities for HPHT; Nitrogen, silicon and hydrogen for CVD - which makes it easy to determine the synthesized stones on the spectrogram.
4. The presence of characteristic fluorescence.

Despite the noted disadvantages, modern synthetic diamonds of good quality are difficult to distinguish from natural even in an expert of a jewelry store or pawnshop, it is only the laboratory. The main disadvantage of artificial diamonds remains a high price, comparable to the natural stones of the same quality.

The error is very common that the synthetic diamond is fianit. This is not true in the root, the synthetic diamond in composition does not differ from its natural fellow, that is, it is a carbon crystal. The fianit is a cubic crystal of zirconium dioxide, which was synthesized by the Fian Institute for the first time, often confusedly confused with a natural stone with a zircon, which, in turn, is a crystal of zirconium silicate. Fianit has two significant disadvantages:

1. Low hardness, due to which it loses the shine, scratches and carries.
2. A relatively low refractive factor, which is where through the faceted fianit often you can often see the light, it makes the feeling that you keep in your hands a glass fake. A well-grated diamond or Moissanite does not miss the light, providing a complete internal reflection of light.

Fianit is currently a very cheap stone, the market price of which is about $ 50 per kilogram, i.e. Less than half of the ruble for carat. Thanks to this fact, the fianit is very profitable to insert into various jewelry and decorate their clothes. Some not bona fide vendors are confused by buyers, calling the fianit of diamond and other misleading names, while unreasonably raising prices for decorations with them. Buying a gold jewelry with fianit is not too intelligent due to the low life of the Fianit, which will noticeably fade in 1-2 years due to micro scratches and scratches. However, a new well-fired fianit on jewelry properties is pretty close to the diamond, i.e. Can provide impressive sparkling and game.

Nevertheless, the fianit on sparkling and the game is relatively different from Swarovski crystals, which are crystal, i.e. Glass with the addition of lead oxide. The addition of lead allows you to achieve some shine and the game, but before the diamond or even the fianita it remains very far. Daniel Swarovski's genius was to put the substrate from aluminum foil from the crystal, which would reflect the light "driving" through the crystal, making it a brighter. Such tricks not a diamond nor, especially, Moissanitu is not needed, because Being well limp, they return all incoming light back up, in the eyes of the observer, which gives them an outstanding brightness and shine.

Received in recent years, as a new jewelry stone is very similar to Diamond. This stone is a silicon carbide crystal, first discovered by the French chemist, Henri Moissan in 1893, which was named after him in 1905. In natural form, Moissanite is found in very small grains and in a meteorite substance. A few years ago, the American firm Charles & Colvard patented the method of producing synthetic moussanite jewelry quality. Moissanite is most noteworthy in that the diamond is superior to the properties of the refraction coefficient and dispersion, which allows it to sparkle and play a stronger diamond. In addition, it is practically not inferior to a diamond of hardness, i.e. It does not scratch and will not fade, unlike Fianita.

Colorless Moissanites have color characteristics comparable with artificial diamonds, i.e. I-k (6-7) for conventional moussanitis and G-H (4-5) for HPHT technology processed. HPHT-refrigeration forever improves the color of the stone, restoring the disturbed links in the crystal, with the process of 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, for this we need special mowers-testers, which are not so common.

In addition to the optical properties, the important advantage of the Moissanite is the price. With a similar size of the stone, the price of Moissanite will be an order of magnitude lower than both natural and synthetic diamond. In addition, Moissanite can be made almost any size, in contrast to a synthetic diamond, the weight of which is currently limited by the values \u200b\u200bof about 1.5-2 carats.

Note! At the moment, the only manufacturer of high-quality jewelry moussanites is Charles & Colvard, the technology of production of synthetic moussanites is patented worldwide, incl. and in Russia. The action of the patent does not apply to a number of Asian countries, such as India and Thailand, which are currently openly selling their low-quality mobsants on the Internet. Buying a synthetic jewelry insert - Moassanite, always specify the presence of a plastic card certificate from Charles & Colvard, which gives you the right to a lifelong warranty!

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

We offer to visit the widest catalog of jewelry with moussanites on the website of our online store BRIGHT SPARK. In our articles, you can read more detail with