Physical and mechanical properties

The main distinguishing features of diamond are the highest hardness among minerals (but at the same time brittleness), the highest thermal conductivity among all solids 900-2300 W / (m · K), high refractive index and dispersion. Diamond is a dielectric. Diamond has a very low coefficient of friction against metal in air - only 0.1, which is associated with the formation of thin films of adsorbed gas on the crystal surface, which play the role of a kind of lubricant. When such films are not formed, the coefficient of friction increases and reaches 0.5-0.55. The high hardness gives the diamond exceptional abrasion resistance. Diamond is also characterized by the highest (in comparison with other known materials) modulus of elasticity and the lowest compression ratio. The crystal energy is 10 5 J / g-at, the binding energy of 700 J / g-at is less than 1% of the crystal energy.

The melting point of diamond is 3700-4000 ° C at a pressure of 11 GPa. In air, diamond burns at 850-1000 ° C, and in a stream of pure oxygen it burns with a faint blue flame at 720-800 ° C, ultimately converting completely into carbon dioxide. When heated to 2000 ° C without air access, the diamond transforms into graphite in 15-30 minutes. The average refractive index of colorless diamond crystals in yellow is approximately 2.417, and for different colors of the spectrum it varies from 2.402 (for red) to 2.465 (for violet). The ability of crystals to break down white light into its individual constituents is called dispersion. For diamond, the variance is 0.063.

One of the important properties of diamonds is luminescence. Under the influence of sunlight and especially cathode, ultraviolet and X-rays, diamonds begin to luminesce - they glow in different colors. All types of diamonds glow under the influence of cathode and X-ray radiation, and only a few under the influence of ultraviolet radiation. X-ray luminescence is widely used in practice to extract diamonds from rocks.

Structure

Each colored diamond is a completely unique piece of nature. There are rare colors of diamonds: pink, blue, green and even red.

Examples of some colored diamonds:

• Porter Rhodes (blue).

Diamond diagnostics

In order to distinguish a real diamond from its imitation, a special "diamond probe" is used, which measures the thermal conductivity of the stone under study. Diamond has a much higher thermal conductivity value than diamond substitutes. In addition, the good wettability of the diamond with fat is used: a felt-tip pen filled with special ink leaves a solid line on the surface of the diamond, while on the imitation surface it crumbles into separate droplets.

Finding diamonds in nature

Cut diamond

Diamond is a rare, but at the same time quite widespread mineral. Commercial diamond deposits are known on all continents except Antarctica. Several types of diamond deposits are known. Already several thousand years ago, diamonds were mined on an industrial scale from alluvial deposits. Only towards the end of the 19th century, when diamondiferous kimberlite pipes were first discovered, did it become clear that diamonds did not form in river sediments.

There is still no exact scientific data on the origin and age of diamonds. Scientists adhere to different hypotheses - magmatic, mantle, meteorite, fluid, there are even several exotic theories. Most are inclined to magmatic and mantle theories, to the fact that carbon atoms under high pressure (usually 50,000 atmospheres) and at a great depth (about 200 km) form a cubic crystal lattice - the diamond itself. Stones are carried to the surface by volcanic magma during the formation of the so-called "explosion tubes".

The age of diamonds, according to some studies, can be from 100 million to 2.5 billion years.

There are known meteorite diamonds of extraterrestrial, possibly pre-solar origin. Diamonds are also formed during impact metamorphism during the fall of large meteorites, for example, in the Popigai astroblem in northern Siberia.

In addition, diamonds were found in the top rocks in the associations of ultrahigh pressure metamorphism, for example, in the Kumdykul diamond deposit in the Kokchetav massif in Kazakhstan.

Both impact and metamorphic diamonds sometimes form very large-scale deposits, with large reserves and high concentrations. But in these types of deposits, diamonds are so small that they have no industrial value.

Extraction and deposits

Commercial diamond deposits are associated with kimberlite and lamproite pipes associated with ancient cratons. The main deposits of this type are known in Africa, Russia, Australia and Canada.

According to the materials of the Kimberley Process, world diamond production in value terms in 2008 amounted to $ 12.732 billion (up 6.7% compared to the previous year).

The search for diamonds in Russia was carried out for almost a century and a half, and only in the mid-50s were the richest primary diamond deposits discovered in Yakutia. On August 21, 1954, geologist Larisa Popugaeva from the geological team of Natalya Nikolaevna Sarsadskikh discovered the first kimberlite pipe outside South Africa. Its name was symbolic - "Zarnitsa". The next was the pipe "Mir", which was also symbolic after the Great Patriotic War. The Udachnaya pipe was opened. Such discoveries served as the beginning of industrial diamond mining on the territory of the USSR. On the this moment the lion's share of diamonds mined in Russia falls on the Yakut mining enterprises. In addition, large diamond deposits are located in the Krasnovishersky District of the Perm Territory, and in the Arkhangelsk Region: the Lomonosov on the territory of the Primorsky region and the Verkhotin deposit (named after V. Grib) on the territory of the Mezensky region.

In September 2012, the media reported that scientists had declassified information about the world's largest deposit of impact diamonds, located on the border of the Krasnoyarsk Territory and Yakutia. According to Nikolay Pokhilenko (director), this deposit contains trillions of carats.

Synthetic diamonds

Background and first attempts

In 1879, Scottish chemist James Hanney discovered that when alkali metals react with organic compounds, carbon is liberated in the form of graphite flakes and suggested that when such reactions are carried out under high pressure conditions, carbon can crystallize in the form of diamond. After a series of experiments in which a mixture of paraffin, bone oil and lithium was kept for a long time in a sealed steel pipe heated to red heat, he managed to obtain several crystals, which, after independent research, were recognized as diamonds. In the scientific world, his discovery was not recognized, since it was believed that diamond could not form at such low pressures and temperatures. A re-examination of Hanney's samples, carried out in 1943 using X-ray analysis, confirmed that the crystals obtained were diamonds, but Professor K. Lonsdale, who carried out the analysis, again stated that Hanney's experiments were a hoax.

Synthesis

The first to synthesize a diamond was Valentin Nikolaevich Bakul in Kiev at the TsKTB of carbide and diamond tools and organized the production of the first 2000 carats of artificial diamonds; since 1963 their serial production has been launched.

Modern methods of diamond production use a gas environment consisting of 95% hydrogen and 5% carbon-containing gas (propane, acetylene), as well as high-frequency plasma concentrated on the substrate, where the diamond itself is formed (CVD). The gas temperature is from 700-850 ° C at a pressure thirty times less than atmospheric. Depending on the synthesis technology, the growth rate of diamonds is from 7 to 180 microns / hour on a substrate. In this case, diamond is deposited on a metal or ceramic substrate under conditions that generally stabilize not the diamond (sp3) but the graphite (sp2) form of carbon. The stabilization of the diamond is primarily due to the kinematic processes on the surface of the substrate. A fundamental condition for diamond deposition is the ability of the substrate to form stable carbides (also at diamond deposition temperatures: between 700 ° C and 900 ° C). For example, diamond deposition is possible on substrates of Si, W, Cr and is not possible (directly, or only with intermediate layers) on substrates of Fe, Co, Ni.

Application

The main types of cut are:

• round (with a standard number of 57 edges)
• fancy, which includes such types of cuts as

“Oval”, “pear” (one side of the oval is an acute angle), “marquise” (an oval with two acute angles, in plan it looks like a stylized image of an eye), “princess”, “radiant”, etc.

The cut shape of a diamond depends on the shape of the original diamond crystal. To obtain a diamond of the maximum value, cutters try to minimize the loss of the diamond during processing. Depending on the shape of the diamond crystal, 55-70% of its weight is lost during its processing.

With regard to processing technology, rough diamonds can be roughly divided into three large groups:

1. "Saubles" - as a rule, crystals of the correct octahedral shape, which must first be sawn into two parts, thus obtaining blanks for the production of two diamonds;
2. "Makblez" - crystals of the wrong or about round shape, are cut in one piece;
3. "Cleavage" - contain a crack and are first split before further processing.

The main centers of diamond cutting are: India, which specializes mainly in small diamonds weighing up to 0.30 carats; Israel cutting diamonds weighing over 0.30 carats; China, Russia, Ukraine, Thailand, Belgium, USA, while in the USA only large high-quality diamonds are produced, in China and Thailand - small, in Russia and Belgium - medium and large. This specialization has developed as a result of differences in the wages of cutters.

Doctor of Technical Sciences Dronova Nona Dmitrievna in 2001 developed a methodology for evaluating rough diamonds, in which, when determining the cost of large crystals, the cost of diamonds that can be obtained from them is predicted.

see also

• NV center - nitrogen-substituted vacancy in diamond

Notes (edit)

1. TSB
2. Phys. Rev. Lett. 70, 3764 (1993): Thermal conductivity of isotopically modified single crystal diamond
3. Dronova Nona Dmitrievna. Changes in the color of diamonds during their processing into diamonds (a systematic approach and experimental research) thesis abstract for the degree of candidate of geological and mineralogical sciences. Specialty 04. 00. 20 - mineralogy, crystallography. Moscow, 1991
4. Yuri Shelementyev, Petr Pisarev The world of diamonds (Russian). Gemological Center of Moscow State University. - A black diamond is called a carbonado. Archived from the original on August 23, 2011. Retrieved September 8, 2010.
5. Science and technology, October 14, 2002
6. Coffee room | Neva, 2003 N9 | Evgeny Treyvus - Calvary of geologist Popugaeva
7. the 1957 Lenin Prize was awarded to other geologists. Only in 1970, Popugaeva was awarded an honorary diploma and the sign "Discoverer of the deposit"
8. Scientists have declassified a deposit of impact diamonds in Siberia, Lenta.ru(September 16, 2012). Retrieved September 18, 2012.
9. "Large diamond - from small ones"
10. B. F. Danilov "DIAMONDS AND PEOPLE"
11. life strategy of a creative person
12. Journal "Universities"
13. Technology of production and purification of detonation diamonds // Solid State Physics, 2004, volume 46, issue 4. - P. 586
14. lenta.ru: "New technology will make it possible to create diamonds of any size" based on materials from "New Scientist"
15. New n-Type Diamond Semiconductor Synthesized
16. Ekimov, E. A .; V. A. Sidorov, E. D. Bauer, N. N. Melnik, N. J. Curro, J. D. Thompson, S. M. Stishov (2004) Superconductivity in diamond. Nature 428 (6982): 542-545. DOI: 10.1038 / nature02449. ISSN 0028-0836. Retrieved on 2010-02-22.
17. Superconductivity in Polycrystalline Diamond Thin Films

Literature

• Dronova N.D., Kuzmina I.E. Characterization and evaluation of rough diamonds. - M .: MGGU, 2004 .-- 74 p.
• Epifanov V.I., Pesina A. Ya., Zykov L.V. Technology of processing diamonds into diamonds. - Tutorial for environments. Vocational school. - M .: Higher school, 1987.
• Orlov Yu.L. Mineralogy of diamond. - M .: Science, 1984.

Links

	Portal "Geology"

Data-lazy-type = "image" data-src = "https://karatto.ru/wp-content/uploads/2017/08/almaz-1.jpg" alt = "(! LANG: stone diamond" width="300" height="200">!} Diamond is a stone that can be safely called the most famous on the whole Earth. It possesses extraordinary physical characteristics and impresses with its beauty. Since ancient times, it has been used for jewelry, and sometimes even acted as the hardest currency. Many legends are associated with the history of its origin, and its medicinal and magical properties are amazing to this day.

Stone with an ancient history

Even according to the most conservative estimates, the history of diamonds goes back many millions of years. Many scientists are inclined to believe that the age of these precious minerals may well be equal to the age of our planet. This explains the number of myths that enveloped his appearance. The origin of diamonds is associated with India, where for thousands of years seekers of gems of extraordinary beauty went. It was there, about three thousand years BC, that these stones became widespread. They were not subjected to any processing, leaving them in their natural state in the treasuries.

The diamond reached the European continent much later, when Alexander the Great found out about it. He organized a trip to India to take possession of hitherto unseen jewels. Legend has it that the brave warrior had to fight the snakes that stood guard over these riches.

And only by the end of the Middle Ages in the Belgian city of Bruges, where there was a real Mecca for people who traded in gems, did they figure out how to give a diamond the shine and sparkle that we are already used to. They began to cut it, and a diamond stone appeared, which meant "brilliant". Thanks to its sparkling facets, it gained incredible popularity and became even more appreciated. The stone began to be mined in very large volumes, and Indian deposits were depleted. But this only spurred an active search for new ones, and such were soon found in Brazil.

Png "alt =" "width =" 60 "height =" 51 "> Now mining is carried out in Australia, on the African continent, in Russia.

The old name of the diamond among the inhabitants of India sounded like "fariy", the Romans gave him the name "diamond". The Greeks appreciated its qualities and began to call it "adamas", which meant "indestructible", "unsurpassed", and the Arabs called it "almas", which means "the hardest" in Russian.

Properties and basic characteristics

Today, there are several theories about how diamonds are formed. For example, according to one of them, diamond appears in nature when the temperature of silicates (silicon-oxygen compounds) in the mantle of the Earth's crust decreases. On the surface, they find themselves after strong deep explosions. In addition, it is believed that these crystals were formed during the fall of meteorites as a result of the simultaneous exposure to high pressure and temperature.

Png "alt =" "width =" 47 "height =" 78 "> The diamond, the formula of which is denoted by one letter C, was previously mined by careful washing of sea or river sand deposits. into other rocks.

But when kimberlite pipes were discovered at the end of the nineteenth century, mining began in a different way. The plots received this name rock containing valuable minerals with a vertical conical shape. .jpg "alt =" (! LANG: stone diamond" width="250" height="181">!}
It is interesting how a rough diamond looks like - these are small (up to 5 mm) particles, matte and rough. Small crystals can grow together.

The physical properties of diamond distinguish it from other minerals, and yet it consists only of carbon atoms. Its most amazing qualities are as follows:

1. The density of a diamond on the Mohs scale is 10. This is the highest value that confirms the exceptional hardness of a diamond. It is extremely difficult to process it, because it damages any material, and itself remains without any traces.
2. The ability of a stone to generate electrical impulses if charged particles interact with it is also surprising.
3. The properties of diamond are also interesting to resist the action of strong acids. They cannot have any effect, but when reacting with melts of alkali, saltpeter and soda, an oxidation process occurs that can "burn" the sample.
4. The melting point of diamond is 3700-4000C °. If a stream of oxygen is directed at the sample, then at a temperature of about 800C ° it will light up with a blue flame. At 1000C ° it will burn out, and heated up to 2000C ° in a vacuum it will turn into graphite.

The structure of the diamond is also interesting, which explains its incredible strength. The crystal lattice of a diamond has the shape of a cube, at the tops of which and inside are carbon atoms, a strong bond between which gives the mineral its hardness.

Areas of use

Data-lazy-type = "image" data-src = "https://karatto.ru/wp-content/uploads/2017/08/almaz-3.jpg" alt = "(! LANG: stone diamond" width="220" height="167">!}
The use of diamond is not limited to use in jewelry industry, in which preference is given only to specimens of the highest quality.

The use of diamonds is widespread in a wide variety of fields, including:

• Medical devices and instruments. In the field of medicine, the use of transparent crystals is very wide. Thanks to such devices, which allow making thin incisions, the healing time in the postoperative period is accelerated. Scalpels made from this material remain sharp for a long time. The structure of the diamond makes it possible to use it in the production of implants.
• The high thermal conductivity of diamond makes it indispensable for use in electronics to prevent overheating of devices.
• The properties and composition of the diamond explain its use in telecommunications. It is prized for its ability to withstand surges in voltage and temperature.
• It is also used in the mining industry to add efficiency to a drill bit.

Interestingly, only 15% of the crystals that are mined in the world can be used to cut them and get diamonds. About 44-46% are “conditionally fit” to be cut. The remaining percentage of the extracted raw materials goes just for industrial and production needs.

How is a diamond made from a diamond?

Many people wonder what a diamond is. In fact, this is still the same diamond, only cut. Processing takes place in several stages, during which various flaws are removed on the crystal. The stones are ground and polished.

Jpg "alt =" (! LANG: 57 facets round diamond" width="200" height="192">!} The cutting process is very long and laborious. To give the crystal the desired shape and create even edges on the surface of the hardest mineral, cast iron discs are used, on which diamond spraying is applied. It is important to position the edges correctly, considering how the light will fall on them. The art of cutting is about making the stone shine with all the colors of the rainbow. The properties of a diamond allow it to refract light rays in different ways, which is what causes such a bright sparkle. These properties are most strongly revealed when a round cut with 57 facets.

As a result of cutting, the size of diamonds is significantly reduced, but this does not affect the cost. A large sample can take months to complete. There are three main types of crystal cutting for this type of stones:

• For processing round pebbles, a diamond look is used. In this case, it is important that a checkerboard pattern is maintained for the triangular or diamond-shaped faces on each tier.
• Rectangular samples are stepped cut, in which triangular or trapezoidal edges run one above the other.
• For cutting small samples, the "rose" or "rosette" method is used.

The characteristics of diamonds also differ in the degree of transparency. Natural minerals cannot boast of absolute purity and have various inclusions. The fewer such defects are, the higher the cost.

Variety of colors

Most people mistakenly believe that the variety of diamond is limited only to transparent colorless crystals. In fact, there are quite a few different color variations, which are sometimes priced much more expensive than the classic ones.

Jpg "alt =" "width =" 80 "height =" 83 "> The yellow diamond is quite common. The mineral received this color thanks to nitrogen atoms that penetrated into its crystal lattice. The richer this color, the more expensive the sample will cost. There are also darker variations found in Australia. There you can find both a cognac diamond and a red diamond.

Jpg "alt =" "width =" 80 "height =" 83 "> The blue diamond is a real rarity. It may be a naturally occurring variety, given its hue from the presence of atoms of a chemical such as boron. A blue diamond can also be obtained by refining a mineral.

Jpg "alt =" "width =" 80 "height =" 83 "> But the blue diamond (its large specimens) is so rare that only holders of luxurious collections can afford it. More common is diamond, which turns blue as a result of heating and increasing pressure.

Every jeweler is not averse to getting a green diamond in his collection, which got its color due to natural radiation. Red diamonds are even less common. They, like a pink diamond, are mined in the deposits of Australia.

The types of diamonds do not end there. There are even black and white diamonds.

Extraordinary properties

Data-lazy-type = "image" data-src = "https://karatto.ru/wp-content/uploads/2017/08/almaz-5.jpg" alt = "(! LANG: gold ring with diamond" width="200" height="136">!}
In the old days, diamonds were attributed to a variety of amazing properties. Even modern experts note the incredible energy of this mineral. Its effect on the human body has often been used to get rid of various ailments, both physical and mental. They are still used in the following areas of medicine:

1. With the help of these gems, you can solve heart problems. The stone will help to normalize the work of blood vessels and heart muscle, lower blood pressure.
2. Iridescent crystals have a positive effect on those people who have mental problems. The impact of the stone will relieve stress, calm the nerves, and help normalize sleep.
3. The energy of the stones has a good effect on women's health, helping to heal from a number of gynecological problems.
4. The mineral is also famous for its anti-inflammatory properties. With its help, you can cope with dermatological problems. Provide a general strengthening effect on all internal organs.

To feel for yourself healing power stone, you can put the crystal in water for 24 hours, and then drink this diamond infusion, which can strengthen the immune system and give tone.

Jpg "alt =" (! LANG: diamond ring" width="200" height="244">!} Magical properties the diamond is also active. He becomes a powerful protector of his owner, protecting him from any negative impact from the outside. In ancient times, rulers always took a diamond with them to feasts, knowing that it could prevent poisoning. He will be able to give a person with pure thoughts self-confidence, prosperity in his personal life, success in his career. It has been used since ancient times to perform magic rituals. A yellow stone is especially effective in this case. The red crystal is so powerful that not everyone will be able to curb it. But the white one can become a talisman for any person.

He will reveal his qualities if you combine it with gold and wear it on your left hand. The ring grants men good luck in the game and success with women. Beautiful earrings or a necklace will add charm to the ladies and help to find love. The stone will most actively reveal its power to Aries, but it is better for Pisces to choose another talisman.

The mystery of the diamond excites many even now. This extraordinary stone is fraught with many still unexplored qualities. Some of them are associated with mystical stories. For example, the "Hope" crystal brought only misfortune to its owners.

The sizes of the found gems are also surprising. When the Cullinan diamond was found at one of the mines, it weighed more than three thousand carats. The great popularity, which is not surprising, led to the fact that scientists wanted to make an artificial variation of it. So in the twentieth century, acting on graphite by pressure and temperature, synthetic analogs were obtained. It is very difficult to distinguish them from real ones. Often only professionals can cope with such a task.

Png "alt =" "width =" 80 "height =" 80 "> To distinguish an original from a fake, you need to pay attention to the number of edges (the classic cut assumes 57) and their clear outline without double vision when viewed through a magnifying glass that magnifies 12 times.

• A real specimen cannot be scratched even by rubbing it with sandpaper.
• If you hold it in your hand, it will stay cool, while a fake will quickly heat up to body temperature.
• And if you drop a drop of fat on the surface, it will remain unchanged, while on a fake it will first break down into smaller droplets.

Despite its amazing hardness, diamond jewelry must be stored with extreme care. If dirty, wash them with soapy water and keep them separate from other jewelry. Do not neglect the help of jewelers. They will be able to check the attachments and clean the stone with ultrasound.

This state, located on the border of crystalline and molten forms, will help not only to better understand the structure and characteristics of diamond, but also reveal the secrets of distant planets.

"Diamonds can be called a chemical compound familiar to the Earth. However, in order to melt it, just high temperature is not enough - you also need extremely high pressure, which, in turn, interferes with the regulation of heating," says one of the authors of the study, Hermann Eggert.

Scientists once managed to melt a diamond, but during that experiment, the scientific team was unable to properly regulate the process and measure the parameters. We can say that the result of that experience came about by accident.

Diamonds are an extremely durable material, and this alone makes melting it an extremely difficult task. But, in addition, there is another feature that makes the process almost impossible. The fact is that when the temperature rises, diamonds do not want to preserve their nature and change their physical properties, turning into graphite. And already this compound turns into liquid. Scientists had to go for a trick - to bring the diamond to the point where it begins to turn into graphite, and keep it in it.

The gas giants Uranus and Neptune are one of the few places in the known part of the Universe where ultra-high temperatures combine with ultra-high pressure. To replicate this natural environment, Eggert and his colleagues placed a natural diamond weighing ten carats and half a millimeter thick in a laser machine capable of generating tremendous pressure.

At a pressure 40 million times higher than the pressure on Earth at sea level, the diamond has turned into a liquid substance. After that, scientists began to gradually reduce the pressure and temperature in the installation. At around 11 million times the normal pressure on Earth and a temperature of about 50,000 Kelvin, hard fragments began to form in the diamond liquid. Experimentally, it was possible to establish that the process of their formation is gaining momentum with a decrease in pressure while maintaining the temperature at a constant level.

The further behavior of the sample amazed the scientists. Diamond crumbs did not stick together, but floated in a liquid medium, just like icebergs float in the vast oceans.

Most materials in liquid form have a lower density than solid. The only exception is water, since the density of ice is always less than that of liquid water. The molten diamond exhibits the same qualities.

Analysis shows that Neptune and Uranus are ten percent carbon. Therefore, Eggert believes, the existence of diamond seas on these planets is quite possible. Moreover, such formations would fit perfectly into the theory, since they can explain one of the interesting riddles these gas giants.

On Earth, the magnetic poles almost coincide with the geographic poles. And on Uranus and Neptune, the axis of the magnetic field is sharply shifted from the axis of rotation - the difference is about 60 degrees. The existence of a diamond ocean, which is capable of reflecting and refracting magnetic waves, could well provide an explanation for this phenomenon.

Ilya Torbaev, an employee of the Institute of Space Research, Doctor of Geological and Mineralogical Sciences, spoke about the diamond seas and diamond shores of Uranus and Neptune.

“From a physical point of view, the proposed model has no obvious flaws. Yes, we are accustomed to the fact that for the Earth, diamond is a unique mineral. But this uniqueness is due only to the lack of sufficient conditions on our planet for the formation of such chemical compounds.

Uranus and Neptune, on the other hand, seem to be created for the synthesis of similar substances. The high carbon content, extreme pressure, and high temperature could have caused diamond to become as widespread there as silicon is on Earth. While the physicochemical aspect of Eggart's experiment is beyond doubt, the astronomical part requires verification and proof. But they will have to wait - the next expeditions to Uranus and Neptune are planned only for 2025-2030. "

Good day, Dear friends... Diamond is incredibly resistant to all kinds of influences from the outside world. But even so, there is still a diamond melting point, which can only be achieved if certain factors are observed.

In fact, measuring the melting point of diamonds is not easy. The thing is that high pressure also exerts an effect. Otherwise, there is a risk of turning the stone back into graphite.

Experiments with the melting point of diamonds

In this story, the National Livermore Laboratory. Lawrence. After all, scientists at the University of California conducted an unusual experiment, as a result of which it turned out that the diamond melts at a temperature of 3700-4000 degrees Celsius and at a pressure of 11 GPa. The experiment was carried out back in 2010.

Unlike many common solids, diamond cannot be liquefied by the normal increase in ambient temperature.

Eggart John, one of the process leaders, shared these observations during the experiment. He also said that for such a state, the diamond must be additionally kept under very high pressure. As you might guess, it is very difficult to measure the temperature of a diamond.

But pressure is indispensable: in air, diamond combustion is carried out at a temperature close to 1000 degrees Celsius, and in a vacuum at 2000 degrees, it turns into graphite (in this case, reverse side the process cannot be reversed, at best you will get a synthetic diamond, inferior to its counterparts). There is no intermediate state in both cases.

Moreover, the experiment on the study of the mineral was carried out at the end of the 17th century by Italian scientists, who decided by all means to fuse several specimens into a single whole. As a result, it was possible to find out only the melting point of the stone.

Also at one time it was possible to find out that melting with ultraviolet rays also cannot be achieved. Indeed, in this case, the mineral simply begins to turn into carbon dioxide. For this reason, it was not possible to create ultraviolet lasers using stone - they simply become unusable. But for ordinary diamonds, things are not so bad. Indeed, for the complete disappearance of one microgram of a mineral, it will take a long 10 billion years.

Main experiment progress

And here is the course of the experiment itself, conducted in 2010:

1. Scientists took a very small diamond (1/10 carat).
2. Shock waves were generated using nanosecond laser pulses, creating tremendous pressure.
3. When the pressure reached 40 times the atmospheric pressure at sea level, the diamond reached a liquid state.

But it didn't end there. Scientists began to lower the pressure and lower the temperature. As a result, it turned out that the diamond begins to return to a solid form (albeit in pieces) at a pressure of 11 million atmospheres and 50,000 Kelvin. At the same time, these pieces floated in the remaining "broth" like ice floes in the sea. Scientists decided to further lower the pressure, but not change the temperature. And the diamond began to behave like ordinary water - even more "icebergs" began to appear in it, the formations themselves became larger.

Unusual hypotheses

Based on such experiments, conclusions were drawn about the possibility of the existence of similar conditions on Uranus and Neptune. The fact is that both of these planets are made up of carbon for a significant 10%.

There is a version that the oceans of molten diamond could be the basis for an unusual magnetic field for Neptune and Uranus, because their poles are spaced apart (!). That is, the magnetic pole does not coincide with the geographic pole.

But for now, hypotheses remain just hypotheses. After all, sending satellites to both planets or trying to simulate their atmospheres on Earth is difficult and expensive. But one day we will know for sure what is really going on there.

By the way, if you are interested in the topic of space and these unusual planets, then we suggest you watch a training video about them.

Secrets of the Universe precious stones not yet fully disclosed. Check back often and learn a lot about these amazing minerals. See you later!

Team LubiStones

The fact that diamonds burn was proven back in the 17th century. But, today this topic flashed with renewed vigor, attracting the attention of not only scientists, but also ordinary people. The "irresistible" stone became the main object of research. This is because with the development of technology, the need for diamonds has increased. Read the article and you will find out how humanity learned about the flammability of the mineral, what role Lavoisier played in its history, and what these experiments gave us.

On the waves of history ...

Inquiring minds at all times have put forward the most insane theories. Unsurprisingly, they were interested in the diamond and its properties. The stone is not only one of the most durable in the world, but also the most expensive. It was only possible to determine that the diamond was burning in the 17th century.

The credit goes to the English physicist Boyle. He managed to burn the diamond through the lens, aiming at it Sunray... But, attempts to repeat the experiment by French scientists have failed. They placed the stone in a melting vessel, and all they achieved was dark bloom on crystals.

Antoine Lavoisier's contribution to crystal studies

The French physicist Antoine Lavoisier made a great contribution to the study of the mineral. He proved that diamonds burn in the presence of air. For his experiment, he:

• placed a stone in a glass vessel;
• filled it with oxygen;
• clogged.

Using a lens, he heated the diamonds, after which they burned completely with a faint blue flame. But no ash was found in the flask. Having examined the air in the flask, he found out that carbon dioxide had appeared in it.

It is interesting that Lavoisier, with his experiments, did not try to prove that a diamond can be burned - it happened by accident. The essence of his experiments was to refute the phlogiston theory.

Carrying out experiments on the combustion of substances in sealed capsules, Lavoisier could not attract the attention of the "scientific community" to them. To remedy this, he announced that he would burn a piece of diamond. Such a move proved the effectiveness of his work and revealed to the world one of the mysteries of the diamond.

The discovery that turned the world upside down

Everything that we now consider habitual depended on whether the diamond caught fire or not. First, thanks to Lavoisier's experiment, the phlogiston theory was rejected. According to her, a reaction always requires two substances. One is capable of giving, the other is capable of receiving. It was replaced by the law of conservation of energy: nothing comes out of nowhere, and does not disappear into nowhere.

Thanks to this law, it was possible to find out that, when burned, a diamond turns into carbon. And this gave us, secondly: if carbon can be obtained from diamond, then there must be a reverse reaction.

Developing this theory, scientists found out that diamond can be synthesized. The discovery had a wide resonance, because the mineral is used in many spheres of life. The ability to obtain it artificially is an unlimited supply of an invaluable resource.

Nature's Joke: Chameleons Among Gems

As we said, diamonds begin to burn at temperatures above 720 degrees. While experimenting with some stones, scientists noticed that reaching the 120-150 g mark, the mineral changes color. This led them to an interesting discovery.

There are chameleon diamonds in nature. Usually, they have an olive tint. But if they are heated, the color changes to a deep brown or orange-yellow. The effect is short-lived. If you continue to act on the stones, they burn out.

A chameleon diamond can change its color in the dark, if it stays there for a long time. Scientists still cannot solve this riddle. Having carried out 39 tests at the same time, they could not agree. Some believe that the reason is the impurity of hydrogen, others - that the stone acquires luminescent properties.

Tell your friends about it by reposting.