Hello dear friends. Many people like the wonderful play of light in the facets of real diamonds. Over time, a simple interest requires more and more immersion in the topic of precious stones, namely diamonds. I would like to know more about their structure, which allows stones to be so strong. The interest is doubly enhanced by the fact that a real stone at home is quite difficult to damage, and the stone is not going to fade over the years. The structure of the diamond is truly amazing.

Graphite and diamond are of the same nature, the same origin. After all, they are based on the well-known carbon. Until now, it remains only to be amazed at how only substances that are strikingly different from each other can be obtained from the same element. What is the structure of an uncut diamond?

Diamond structure

The crystal structure of the stone has a very harmonious structure and connection of atoms. This is not surprising: carbon atoms tend to be located in the center, and the top points (tops) in this form are only the carbon atoms closest to each other. By the way, the density of adamant is precisely explained by the fact that the atoms of the unit cell are bound by a covalent bond.

You can see the structure of the crystal lattice in this small video:

The most interesting thing is that the facets of a diamond appear only when it is cut. That is, it has nothing to do with the shape of the crystal.

In general, the mineral, as already noted, is almost one hundred percent carbon. However, in this case, you can find a lot of impurities in it (albeit within only one percent). Silicon, magnesium, nitrogen - what can you not find in that insignificant share of additional substances that a diamond has. And this is not a complete list.

In this case, the shape of the diamond crystal is a tetrahedron, that is, in fact, a regular pyramid with four triangles as planes. Any of the lattices of the mineral has a cubic shape, hence the name of the crystal lattice.

Due, among other things, to its structure, a diamond is often used in technology and in many industries, which you can read about here.

Physical properties of diamond

In addition to general information about the structure of the stone, with the help of such information, you can get some other information regarding its properties.

As mentioned earlier, diamond is the hardest among the substances existing on Earth (the density on the Mohs scale is oriented towards it at its maximum value of 10). But some varieties of the mineral, although they have a similar structure, but at the same time have much lower hardness. For example, the same corundum is much less hard - diamond exceeds it in this quality by about 150 times.

The same graphite is much softer for one simple reason - a fundamental difference in the structure of the crystal lattice.

Experiments

By the way about burning. Some craftsmen are doing combustion experiments in laboratories. Of course, these are specialists, it is not worth repeating this (and it is very difficult). The process of one of these experiments can be seen in the video:

More facts about stones and their features await you further. Check back frequently and share your experiences using the social media buttons. See you soon!

Team LubiStones

Diamond is the king of all minerals. The hardest, the most expensive ... what epithets this mineral has not received. There is only one thing, but diferambs usually sing not to all diamonds, but only to jewelry - diamonds, and this is a very small percentage of all mined stones. Right there we will try to tell you about all the diamonds and about those that jewelers cut in order to make a beautiful ring or necklace and about those without which many branches of the national economy are impossible. In an ordinary glass cutter, there is also a diamond, they insert this stone into drill bits. So not all diamonds go to the jewelry industry. It is difficult to give exact figures, but according to various sources, the share of mined diamonds that can become precious stones ranges from 10 to 20%. And the rest is just used for industrial purposes.

Diamond- cubic polymorphic (allotropic) modification of carbon (C), stable at high pressure. At atmospheric pressure and room temperature, it is metastable, but it can exist indefinitely without transforming into graphite, stable under these conditions. In air, diamond burns at 850 ° C with the formation of CO 2; in vacuum at temperatures above 1.500 ° C it transforms into graphite. The colorless varieties are pure carbon. Colored and opaque diamonds contain impurities of silicon dioxide (SiO 2), magnesium oxide (MgO), calcium oxide (CaO), iron oxide (FeO), iron oxide (Fe 2 O 3), aluminum oxide (Al 2 O 3), oxide titanium (TiO 2); graphite and other minerals are found in the form of inclusions. Diamond varieties:

• Ballas - spherulites of diamond of a spherical or similar form with a radial-radiant structure.
• Board (boart, bort) - diamond aggregates of irregular shape, fine- and coarse-grained.
• Carbonado (carbonado) - latent or microcrystalline diamond aggregates, dense or porous.
• Yakut (yakutite) - a diamond with an abundance of inclusions, due to which it has a dark color, was named after the place of extraction.

Diamond is the hardest mineral. Its hardness is 10 on the Mohs scale and this is the maximum. The absolute hardness of diamond is 1000 times that of quartz and 150 times that of corundum.

The density of the mineral is 3.5-3.52, this is certainly not a record, but also a lot. For diamonds, the characteristic crystal forms are octahedrons and dodecahedrons (tetrahedrons); accretion twins are found; crystals are sometimes characterized by etching patterns, shading, curvature of edges, irregular, distorted crystals are observed.

Crystal structure

Face-centered cube lattice; each atom is surrounded by four others arranged in a tetrahedron. Perfect in the octahedron (111), fragile. P. tr. In powder, it burns on a platinum wire with the formation of carbon dioxide (CO3); when the access of air is stopped and the temperature is 1500 ° C, it turns into graphite. Acid behavior. Insoluble.

Origin

At the moment, there is no exact, scientifically proven theory of the origin of diamonds. There are a variety of hypotheses, but the bulk of scientists are inclined to magmatic and mantle theories. At great depths (120-200 km), carbon atoms under high pressure (45-60 thousand atmospheres) and at high temperatures (900-1300 ° C) form a cubic crystal lattice - diamond. Rocks containing diamonds are brought to the surface using "blast tubes". There are also diamonds of meteorite (extraterrestrial) origin. When large meteorites fall during impact metamorphism, diamonds can also form, for example, in the Popigai astroblem in northern Siberia.

Associated minerals

• in kimberlites: forsterite, phlogopite, pyrope, diopside, ilmenite;
• in placers: ilmenite, garnets, rutile, brookite, anatase, hematite, magnetite, tourmalines, gold, zircon, topaz

Diamonds are also obtained artificially.

Mineral properties

• Origin of name: from the ancient Greek ἀδάμας - indestructible
• Opening year: known since ancient times
• Thermal properties: Diamond has the highest thermal conductivity. In powder it burns on a platinum wire with the formation of carbon dioxide (CO3); when the access of air is stopped and the temperature is 1500 ° C, it turns into graphite.
• Luminescence: In kaodny and X-rays - all varieties luminesce with white-blue light, in UV rays - some, mainly in blue tones, but other colors are also possible
• IMA status: valid, described for the first time before 1959 (before IMA)
• Strunz (8th edition): 1 / B.02-40
• Hey "s CIM Ref .: 1.24
• Dana (7th Edition): 1.3.5.1
• Dana (8th edition): 1.3.6.1
• Molecular weight: 12.01
• Cell parameters: a = 3.5595Å
• The number of formula units (Z): 8
• Unit cell volume: V 45.10 ų
• Twinning: twins of sprouting according to the spinel law are common (111)
• Point group: m3m (4 / m 3 2 / m) -hexoctahedral
• Space group: Fm3m (F4 / m 3 2 / m)
• Density (calculated): 3.515
• Density (measured): 3.5 - 3.53
• Pleochroism: does not pleochroate
• Dispersion of optical axes: strong
• Refractive indices: nα = 2.418
• Maximum birefringence:δ = 2.418 - isotropic, does not possess birefringence
• A type: isotropic
• Optical relief: moderate
• Allocation form: octahedra, dodecahedrons (tetrahedrons); accretion twins are found; spherulites with a radial-radiant structure, irregular, distorted crystals
• Classes on the taxonomy of the USSR: Nonmetals
• IMA classes: Native elements
• Chemical formula: C
• Systema: cubic
• Color: colorless, yellowish, brown, sometimes green, blue, reddish, black
• Feature color: Doesn't have: scratches the test plate
• Shine: fat diamond
• Transparency: transparent translucent opaque
• Cleavage: perfect
• Kink: conchoidal uneven
• Hardness: 10
• Fragility: Yes
• Literature: Diamond. Handbook, K., 1981 Afanasyev V.P., Efimova E.S., Zinchuk N.N., Koptil V.I. Atlas of the morphology of diamonds in Russia. Novosibirsk: Publishing house of SRC SB RAS OIGGM, 2000. Vaganov V.I. Diamond Deposits in Russia and the World (Forecasting Basics). M .: Geoinformmark, 2000.371 p. V.K. Garanin Introduction to the mineralogy of diamond deposits. Moscow: Moscow State University, 1989, 208 p. Garanin V.K., Kudryavtseva G.P., Marfunin A.S., Mikhailichenko O.A. Inclusions in diamond and diamondiferous rocks. Moscow: Moscow State University, 1991, 240 p. Garanin V.K., Kudryavtseva G.P. Mineralogy of diamond with inclusions from kimberlites of Yakutia. Izv. universities. Geol. and intelligence, 1990, N 2, p. 48-56
• Additionally: In powder, it burns on a platinum wire to form carbon dioxide (CO2); when the access of air is stopped and the temperature is 1500 ° C, it turns into graphite. Acid behavior. Insoluble.

Mineral photo

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DIAMOND (Türkic almas, from the Greek adamas - indestructible, invincible * a. Diamond; n. Diamant; f. Diamant; and. Diamante) - a crystalline cubic modification of the native.

Diamond structure... The unit cell of the spatial crystal lattice of diamond is a face-centered cube with 4 additional atoms located inside the cube (Fig.).

The size of the edge of the unit cell is a 0 = 0.357 nm (at t = 25 ° C and P = 1 atm). The shortest distance between two neighboring atoms is C = 0.154 nm. Carbon atoms in the structure of diamond form strong covalent bonds directed at an angle of 109 ° 28 "relative to each other, making diamond the hardest substance known in nature. In the band structure of diamond, the band gap for non-vertical transitions is 5.5 eV, for vertical - 7.3 eV, valence band width 20 eV. Electron mobility mn = 0.18 m 2 / V.s, holes mr = 0.15 m 2 / V.s.

Diamond morphology... Diamond crystals have the shape of an octahedron, rhombododecahedron, cube and tetrahedron with smooth and lamellar-stepped faces or rounded surfaces, on which various accessories are developed. Characterized by flattened, elongated and complexly distorted crystals of simple and combined forms, twins of accretion and growth according to the spinel law, parallel and arbitrarily oriented concretions. The varieties of diamond are polycrystalline formations: the board is conglomerations of numerous small faceted crystals and grains of irregular shape, gray and black; ballas - spherulites of radial-radiant structure; carbonado - cryptocrystalline, dense, with an enamel-like surface or slag-like porous formations, consisting mainly of submicroscopic (about 20 microns) diamond grains, closely intergrown with each other. The size of natural diamonds ranges from microscopic grains to very large crystals weighing hundreds and thousands of carats (1 carat = 0.2 g). The mass of mined diamonds is usually 0.1-1.0 carats; large crystals (over 100 carats) are rare. The table shows the world's largest diamonds recovered from the depths.

Chemical composition... The diamond contains impurities Si, Al, Mg, Ca, Na, Ba, Mn, Fe, Cr, Ti, B number. With the help of a-particles of radioisotope H, N, O, Ar and other elements. is the main impurity that has a great influence on the physical properties of diamond. Diamond crystals that are opaque to ultraviolet radiation are called type I diamonds; all others are type II. The nitrogen content in the overwhelming majority of type I diamond crystals is about 0.25%. Less common are nitrogen-free type II diamonds, in which the nitrogen impurity does not exceed 0.001%. Nitrogen enters the diamond structure isomorphically and forms, independently or in combination with structural defects (vacancies, dislocations), centers responsible for color, luminescence, absorption in the ultraviolet, optical, infrared and microwave regions, the nature of X-ray scattering, etc.

Physical properties... Diamonds can be colorless or with a subtle tint, as well as, to varying degrees, clearly colored in yellow, brown, mauve, green, blue, blue, milky white and gray (to black). When irradiated with charged particles, the diamond becomes green or blue. The reverse process - the transformation of a colored diamond into colorless - has not yet been carried out. Diamond is characterized by a strong brilliance, a high refractive index (n = 2.417) and a strongly pronounced dispersion effect (0.063), which causes a multi-colored play of light in. Typically, diamond crystals exhibit anomalous birefringence due to stresses arising from structural defects and inclusions. Diamond crystals are transparent, translucent or opaque, depending on the saturation of microscopic inclusions of graphite, other minerals and gas-liquid vacuoles. When illuminated by ultraviolet rays, a significant part of transparent and translucent diamond crystals luminesce in blue, blue, and less often yellow, yellow-green, orange, pink and red colors. Diamond crystals (with rare exceptions) luminesce when exposed to X-rays. The glow of a diamond is excited by cathode rays and by bombardment with fast particles. After excitation is removed, afterglow of varying duration (phosphorescence) is often observed. Electro-, tribe- and thermoluminescence is also manifested in diamond.

Diamond, as the hardest substance in nature, is used in a variety of tools for sawing, drilling and processing all other materials. Relative on the Mocca 10 scale, the maximum absolute microhardness, measured by an indenter on the (111) face, 0.1 TPa. The hardness of diamond on different crystallographic faces is not the same; the hardest is the octahedral face (111). Diamond is very fragile and has a very perfect cleavage along the (111) face. Young's modulus 0.9 TPa. The density of transparent diamond crystals is 3515 kg / m 3, translucent and opaque - 3500 kg / m 3, for some Australian diamonds - 3560 kg / m 3; at the bead and carbonado, due to their porosity, it can decrease to 3000 kg / m 3. The clean surface of diamond crystals has a high (contact angle 104-105 °). In natural diamonds, especially in diamonds from alluvial deposits, the thinnest films are formed on the surface, which increase its wettability.

Diamond is a dielectric. Resistivity r for all nitrogen crystals of type I diamond is equal to 10 12 -10 14 Ohm.m. Among the nitrogen-free type II diamonds, crystals are sometimes found in which r is below 10 6 Ohm m, sometimes up to 10-10 -2. Such diamonds have r-type conductivity and photoconductivity, and under the same conditions the photocurrent in type II diamond is an order of magnitude higher than the photocurrent excited in type I diamond. Diamond is diamagnetic: the magnetic susceptibility per unit mass is 1.57.10 -6 SI units at 18 ° C. Diamond is resistant to all acids, even at high temperatures. In melts of alkalis KOH, NaOH and other substances in the presence of O, OH, CO, CO 2, H 2 O, oxidative dissolution of diamond occurs. Ions of some elements (Ni, Co, Cr, Mg, Ca, etc.) have catalytic activity and accelerate this process. Diamond has high thermal conductivity (especially nitrogen-free type II diamonds). At room temperature, their thermal conductivity is 5 times higher than Cu, and the coefficient decreases with increasing temperature in the range of 100-400 K from 6 to 0.8 kJ / mK. The polymorphic transition of diamond to at atmospheric pressure occurs at a temperature of 1885 ± 5 ° С throughout the entire volume of the crystal. The formation of graphite films on the surface of faces (III) of diamond crystals under the influence can occur starting from 650 ° C. In air, the diamond burns at a temperature of 850 ° C.

Prevalence and origin... Diamonds have been found in meteorites, impact rocks associated with meteorite craters (astroblems), in and in them of small size deep mantle rocks of anterior and eclogite compositions, as well as in secondary sources - placers of different age and genesis (, etc. ). There is no consensus on the origin of diamonds. Some scientists believe that diamonds crystallize in the kimberlite pipes themselves during their formation or in intermediate chambers arising at shallow (3-4 km) depths (subvolcanic chambers). Others believe that diamonds form at great depths in the parent kimberlite melt and continue to crystallize as it rises to the top. The idea that diamonds are genetically related to various types of rocks and are removed from them together with other xenogenic material found in kimberlites is most reasonably developed. There are other ideas about the genesis of diamond (for example, crystallization at low pressures using carbon from deep-seated origin and carbonates of the host rocks).

Deposits of diamonds... Diamond-bearing kimberlite rocks and placer deposits formed due to their erosion are of industrial importance. Kimberlites are found mainly on ancient and; they are mainly characterized by tubular bodies, as well as huskies and. The dimensions of kimberlite pipes are from one to several thousand meters in cross section (for example, the Mwadui pipe in Tanzania with parameters 1525x1068 m). More than 1500 kimberlite bodies are known on all platforms, but only a few diamonds have commercial grade. Diamonds are distributed extremely unevenly in kimberlites. Industrial pipes are considered to have a diamond content of 0.4 ct / m 3 and above. In exceptional cases, when pipes contain an increased percentage of high-quality diamonds, it can be profitable to operate with a lower grade, for example, 0.08-0.10 ct / m 3 (Jagersfontein in South Africa). Crystals with a size of 0.5-4.0 mm (0.0025-1.0 ct) predominate in kimberlites. Their weight fraction is usually 60-80% of the total mass of recoverable diamonds. Reserves in individual fields are estimated at tens of million. The largest primary diamond deposits are explored in Tanzania, Lesotho, Sierra Leone, etc.

Enrichment... In alluvial deposits, the rock is first washed in to remove the binding clay mass and separate coarse debris; isolated, loose material is divided into four classes: -16 + 8, -8 + 4, -4 + 2, -2 + 0.5 mm. produced by gravitational methods (wet and air, enrichment in heavy suspensions, in concentration bowls). To extract small diamonds and diamond grit, film and foam are used with preliminary cleaning of the surface. Reagents: amines, aeroflot, fatty acids, kerosene, cresylic acid. For the extraction of diamonds, the most widespread process is the fatty process (for grains with a particle size of 2-0.2 mm), based on the selective ability of diamonds to adhere to fatty surfaces. Vaseline, oil, autol and its mixture with paraffin, oleic acid, nigrol, etc. are used as a fat coating. poor electrical conductor). The X-ray luminescence method is used to extract relatively large diamonds, based on the ability of diamond crystals to luminesce (X-ray luminescent machines).

Application... Diamonds are divided into gem and technical. The former are highly transparent. The most valuable diamonds are colorless ("pure water") or with a good color. All other mined diamonds, regardless of their quality and size, are classified as technical ones. In the CCCP, diamond grading is done according to specifications that are updated as diamond applications expand. Depending on the type and purpose, rough diamonds are classified into categories in terms of quality; in each category, there are groups and subgroups that determine the size, shape, specific conditions for the appointment of diamond crystals. About 25% of the diamonds mined in the world are used in the jewelry industry to make polished diamonds.

Possessing an exceptionally high hardness, diamonds are indispensable for the manufacture of various tools and devices (and, indenters for measuring the hardness of materials, dies, needles for profilometers, profilographers, pantographs, drills, cutters, overhead stones for marine chronometers, glass cutters, etc.). Diamonds are widely used for the manufacture of abrasive powders and pastes, for refueling diamond saws. Some metals, semiconductor materials, ceramics, building reinforced concrete materials, crystal, etc. are processed with a diamond tool. Due to the combination of a number of unique properties, diamonds can be used to create electronic devices designed to work in strong electric fields, at high temperatures, in conditions of increased radiation levels , in aggressive chemical environments. On the basis of diamonds, nuclear radiation detectors, heat sinks in electronic devices, thermistors and transistors have been created. The transparency of diamonds for infrared radiation and the weak absorption of X-rays make it possible to use them in infrared receivers, in chambers for studying phase transitions at high temperatures and pressures.

Synthetic diamonds... In the mid 50s. the development of industrial synthesis of industrial diamonds began. Mainly synthesized are small single crystals and larger polycrystalline formations such as ballas and carbonado. The main methods of synthesis: static - in the metal - graphite system at high pressures and temperatures; dynamic - polymorphic transition of graphite in diamonds when exposed to a shock wave; epitaxial - the growth of diamond films on diamond seeds from gaseous hydrocarbons at low pressures and temperatures of about 1000 ° C. Synthetic diamonds are also used as natural industrial diamonds. The total production of synthetic diamonds significantly exceeds the production of natural diamonds.

/ mineral diamond

"Invincible" is the translation from the ancient Greek name of the hardest mineral found on earth. The high degree of light refraction ensures the play of a gem diamond. Glows in ultraviolet and X-rays, many glow in the dark after exposure to light. The largest deposits in Russia are located in Yakutia and the Arkhangelsk region. For a long time, the diamond is considered the stone of kings, symbolizing strength and power, in India it is considered the main stone of the seventh chakra, which connects a person with the Higher Forces, nourishing the brain, heart and etheric body with its vibrations.

Diamond is the king of all minerals. The hardest, the most expensive ... what epithets this mineral has not received. There is only one thing, but diferambs usually sing not to all diamonds, but only to jewelry - diamonds, and this is a very small percentage of all mined stones. Right there we will try to tell you about all the diamonds and about those that jewelers cut in order to make a beautiful ring or necklace and about those without which many branches of the national economy are impossible. In an ordinary glass cutter, there is also a diamond, they insert this stone into drill bits. So not all diamonds go to the jewelry industry. It is difficult to give exact figures, but according to various sources, the share of mined diamonds that can become precious stones ranges from 10 to 20%. And the rest is just used for industrial purposes.

Diamond is a cubic polymorphic (allotropic) modification of carbon (C), stable at high pressure. At atmospheric pressure and room temperature, it is metastable, but it can exist indefinitely without transforming into graphite, stable under these conditions. In air, diamond burns at 850 ° C with the formation of CO 2; in vacuum at temperatures above 1.500 ° C it transforms into graphite. The colorless varieties are pure carbon. Colored and opaque diamonds contain impurities of silicon dioxide (SiO 2), magnesium oxide (MgO), calcium oxide (CaO), iron oxide (FeO), iron oxide (Fe 2 O 3), aluminum oxide (Al 2 O 3), oxide titanium (TiO 2); graphite and other minerals are found in the form of inclusions. Diamond varieties:

• Ballas - spherulites of diamond of a spherical or similar form with a radial-radiant structure.
• Board (boart, bort) - diamond aggregates of irregular shape, fine- and coarse-grained.
• Carbonado (carbonado) - latent or microcrystalline diamond aggregates, dense or porous.
• Yakut (yakutite) - a diamond with an abundance of inclusions, due to which it has a dark color, was named after the place of extraction.

Diamond is the hardest mineral. Its hardness is 10 on the Mohs scale and this is the maximum. The absolute hardness of diamond is 1000 times that of quartz and 150 times that of corundum.

The density of the mineral is 3.5-3.52, which is certainly not a record, but also a lot. For diamonds, the characteristic crystal forms are octahedrons and dodecahedrons (tetrahedrons); accretion twins are found; crystals are sometimes characterized by etching patterns, shading, curvature of edges, irregular, distorted crystals are observed.

Crystal structure

Face-centered cube lattice; each atom is surrounded by four others arranged in a tetrahedron. Perfect in the octahedron (111), fragile. P. tr. In powder, it burns on a platinum wire with the formation of carbon dioxide (CO3); when the access of air is stopped and the temperature is 1500 ° C, it turns into graphite. Acid behavior. Insoluble.

Origin

At the moment, there is no exact, scientifically proven theory of the origin of diamonds. There are a variety of hypotheses, but the bulk of scientists are inclined to magmatic and mantle theories. At great depths (120-200 km), carbon atoms under high pressure (45-60 thousand atmospheres) and at high temperatures (900-1300 ° C) form a cubic crystal lattice - diamond. Rocks containing diamonds are brought to the surface using "blast tubes". There are also diamonds of meteorite (extraterrestrial) origin. When large meteorites fall during impact metamorphism, diamonds can also form, for example, in the Popigai astroblem in northern Siberia.

Associated minerals

• in kimberlites: forsterite, phlogopite, pyrope, diopside, ilmenite;
• in placers: ilmenite, garnets, rutile, brookite, anatase, hematite, magnetite, tourmalines, gold, zircon, topaz

Diamonds are also obtained artificially.

A bit of history

Five thousand years ago, people became known for their bewitching beauty, enchanting the souls and minds of many, the most beautiful stone - a diamond. Thousands of novels and stories, hundreds of films and millions of human destinies are associated with this enchanting stone. By his nature, he fully justifies his proud name given to him by the ancient Greeks. In translation, diamond means indomitable. HE stubbornly resists the hands of a grinder and the shrewd mind of a scientist, chemical reagents and powerful time.

The ancient Hindus had a conviction regarding the composition of diamonds, or rather the proportions of the main elements of the universe contained in them, i.e. - water, earth, air, sky and energy. If the base of the stone is earth, then the diamond is dense; water - smooth transparent heavy; air - the diamond is sharp and light; if the advantage of heaven is in it, the stone is pure, extremely shiny and has sharp edges; Diamonds, which have the main essence of energy, most often have a blood-red light.

Also, each species was given its own magical properties: the watery diamond gives glory, wealth and satisfaction, the earthy diamond contributes to the conquest of absolute earthly power, the airy ones gave warmth and grace, heavenly health, and those in which energy was the basis - courage, power, hope. Impressed by its splendor and longevity, they dedicated him to their deities and placed him at the head of precious stones.

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• From the history of stone
  

  The extraordinary properties of diamond have given rise to many legends. The ability to bring good luck is just one of the countless properties attributed to a diamond.

• Famous diamonds
  

  Diamond "Kohinor", "Cullinan VI", Raja Maltansky, Orlov

• The name "diamond" comes from the word "adamas"
  

  The diamond has been the number one gemstone ever since its elaborately cut forms, known as diamonds, brought out the perfection of the mineral's amazing properties.

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  The play of colors and brilliance of a diamond is wonderful, but its most remarkable properties are its hardness and chemical resistance.

• The history of the Shah diamond
  

  weighing 90 carats (or 18 g) - yellow, but very transparent, 3 cm long - was found in Central India, probably in 1450.

• The story of the Nadezhda diamond
  

  There are more legends associated with the HOPE diamond than with any other stone in the world. In addition to its size and extraordinary deep blue color, it can boast of the mysterious and mystical status of a cursed stone.

• Crystalline modification of pure carbon
  

  Diamond is a crystalline modification of pure carbon, formed in the deep bowels of the Earth, in the upper mantle at depths of more than 80-100 kilometers, at extremely high pressures and temperatures.

• Where and how diamonds are mined
  

  Currently, diamonds are mined from two types of deposits: primary (kimberlite and lamproite pipes) and secondary - placers.

• Russian cut diamonds
  

  The construction of diamond cutting factories in the USSR began shortly after the discovery of diamond deposits in Yakutia.

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  The cost of diamonds is traditionally calculated in US dollars per 1 carat. Weight, color, clarity, cut quality, known as the 4 "C", are the main factors on which the value of a diamond depends.

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  Evaluation of the cut quality is closely related to the human perception of the stone, since a well-cut stone is perceived by a person as beautiful and evokes positive emotions.

• The history of the diamond begins simultaneously with the history of the diamond!
  

  We have 7 factories in our country, the main of which is located in Smolensk. The quality of Russian white diamonds is considered one of the best in the world. The Alrosa company is engaged in the extraction of diamonds, mainly white and yellow. “Most of the mined (Alrosa) and cut (Crystal) minerals go to the West.

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  Black diamonds, or carbonado, are one of the rarest and most mysterious minerals on our planet. Recently, new confirmation of their extraterrestrial origin has been received.

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  Certified diamonds appeared on the Russian market on September 7, 1997. On this day, German Kuznetsov, then the head of the Gokhran of Russia, held a conference at which he demonstrated to the audience the first certified diamond in Russia, packed in plastic.

• Polycrystalline diamond aggregates
  

  In addition to single crystals, diamonds often form regular and irregular intergrowths.

• Diamond is a rare native element
  

  The hardest and most expensive, the rarest and most attractive, the most chemically resistant and the most brilliant cut.

• Determination of cut quality and visual perception of diamond beauty
  

  The factors that determine the quality of the cut and the perception of the appearance of a diamond by a person can be divided into several main groups ...

• Discoloration of diamonds. Is a crisis imminent in the diamond market?
  

  In the diamond periodicals and on the INTERNET (RapNet) there were reports that the LKI company is starting to sell diamonds, which have been discolored using a special technology, through the POL company, specially created in Antwerp.

Contrary to popular misconceptions, diamonds in nature are not found at all over the entire surface of the earth's crust. Carbon - a non-metal, which is the basis of this mineral, becomes a diamond only when exposed to extremely high temperatures and pressures at a depth of 160 to 480 km. The "cradle" of the overwhelming number of crystals are volcanoes, it is thanks to them that diamonds are closer to the surface, therefore, quarrying is carried out in areas with increased volcanic activity. Some of the minerals are simply washed out from the kimberlite pipes.

The origin of the diamonds is still unclear, and there is still a lot of controversy on this score. Only one thing was precisely determined - the place and time of their formation. Most scientists agree that diamonds originated in the mantle of our planet between 100 million and 2.5 billion years ago. Carbon at a depth of 200 km under the influence of temperatures of 1300 ° C and at a pressure of 4-5 GPa gradually formed a diamond crystal lattice. There are known cases of the formation of diamond deposits at a depth of 700 km.

The most popular theories on which diamonds are formed in volcanic rocks are:

1. Carbon got into solidifying magma as part of hydrocarbons, so diamonds appeared in the upper layers of the planet's crust.
2. The non-metal crystallized very deeply - at a depth of ultrabasic rocks, after which the deposits were carried upward by magma flows.
3. The latter theory is the most popular. Most of the crystals originated in the ultrabasic rock, and some diamonds appeared already in the process of the ascent of this rock to the crustal surface.

Real diamond is a non-metal that is actually not all that rare. The reason for its high cost is that only a small number of deposits are available to mankind, while the main deposits are located too deep underground.