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106-404: The stone is not cut, but polished, and there is a through hole drilled in the lower part. A small pin, capped on both sides with small diamonds , is inserted into it. According to the 1898 inventory, the weight of the gemstone is 389 old carats ; in 1922, the stone was weighed together with the pin and diamonds covering the hole, the weight was 414.3 metric carats. When Alexander Fersman compiled

212-426: A subduction zone . Peter II of Russia Peter II Alexeyevich (23 October 1715 – 30 January 1730) was Emperor of Russia from 1727 until 1730, when he died at the age of 14. He was the only son of Tsarevich Alexei Petrovich and Charlotte Christine of Brunswick-Lüneburg . After Catherine I 's death, Alexander Menshikov controlled Peter II, but was thwarted by his opponents and exiled by Peter. Peter

318-486: A Christie's auction. In May 2009, a 7.03-carat (1.406 g) blue diamond fetched the highest price per carat ever paid for a diamond when it was sold at auction for 10.5 million Swiss francs (6.97 million euros, or US$ 9.5 million at the time). That record was, however, beaten the same year: a 5-carat (1.0 g) vivid pink diamond was sold for US$ 10.8 million in Hong Kong on December 1, 2009. Clarity

424-453: A cigarette lighter, but house fires and blow torches are hot enough. Jewelers must be careful when molding the metal in a diamond ring. Diamond powder of an appropriate grain size (around 50   microns) burns with a shower of sparks after ignition from a flame. Consequently, pyrotechnic compositions based on synthetic diamond powder can be prepared. The resulting sparks are of the usual red-orange color, comparable to charcoal, but show

530-727: A continuum with carbonatites , but the latter have too much oxygen for carbon to exist in a pure form. Instead, it is locked up in the mineral calcite ( Ca C O 3 ). All three of the diamond-bearing rocks (kimberlite, lamproite and lamprophyre) lack certain minerals ( melilite and kalsilite ) that are incompatible with diamond formation. In kimberlite , olivine is large and conspicuous, while lamproite has Ti- phlogopite and lamprophyre has biotite and amphibole . They are all derived from magma types that erupt rapidly from small amounts of melt, are rich in volatiles and magnesium oxide , and are less oxidizing than more common mantle melts such as basalt . These characteristics allow

636-408: A crown of diamond things that are removed from the great and lesser crowns”. However, the wedding did not take place due to the death of the emperor on January 19, 1730. For the crown of Anna Ioannovna , which was made in great haste, the craftsmen were given three large lals, including the one that was in the crown of Peter II, and it has not yet been possible to establish which of these three stones

742-452: A diamond to fluoresce. Diamonds can fluoresce in a variety of colors including blue (most common), orange, yellow, white, green and very rarely red and purple. Although the causes are not well understood, variations in the atomic structure, such as the number of nitrogen atoms present are thought to contribute to the phenomenon. Diamonds can be identified by their high thermal conductivity (900– 2320 W·m ·K ). Their high refractive index

848-614: A few months in the summer of 1727, "[n]ot even Peter the Great was so feared or so obeyed", according to the Saxon ambassador. Menshikov became arrogant and domineering. He issued orders to the Emperor himself and then removed a silver plate that Peter had just given as a gift to his sister Natalya . To which the Emperor replied, "We shall see who is emperor, you or I." Soon, however, Menshikov became sick, and his opponents took advantage of his illness. Under

954-475: A gemstone. Because it can only be scratched by other diamonds, it maintains its polish extremely well. Unlike many other gems, it is well-suited to daily wear because of its resistance to scratching—perhaps contributing to its popularity as the preferred gem in engagement or wedding rings , which are often worn every day. The hardest natural diamonds mostly originate from the Copeton and Bingara fields located in

1060-479: A good ruler. He hated learning and thinking about national affairs. He was totally engrossed in amusements, and was kept under someone else's influence." In late December 1729 Peter II fell dangerously ill. His condition deteriorated sharply after the frosty Epiphany Day (17 January  [ O.S. 6 January]  1730), when he participated in a feast. He was then rushed into the Lefortovo palace , standing at

1166-554: A lal stone” to the head of the Department of Siberian Affairs, Prince Fyodor Romodanovsky . Romodanovsky sent the stone with Gagarin to Peter I , and the prince showed it to the tsar in Poland , in Grodno . Peter I “deigned to accept that stone from me himself”. In 1721, the stone was already in the possession of Prince Alexander Menshikov. Gagarin did not know why there were no records of this in

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1272-585: A meeting of the Supreme Privy Council on October 2, 1727, a decision was made to “make the crown again”. The creation of this crown, like the previous one, was entrusted to a group of court jewelers, headed by master Samson Larionov  [ ru ] . It was topped with a cross of nine “quadrangular” diamonds of Greek cut, fixed on a huge lal (as red and pink spinels and tourmalines were called in Russia at that time) worth 60 thousand rubles - most likely

1378-475: A metallic fluid. The extreme conditions required for this to occur are present in the ice giants Neptune and Uranus . Both planets are made up of approximately 10 percent carbon and could hypothetically contain oceans of liquid carbon. Since large quantities of metallic fluid can affect the magnetic field, this could serve as an explanation as to why the geographic and magnetic poles of the two planets are unaligned. The most common crystal structure of diamond

1484-403: A pale blue flame, and continues to burn after the source of heat is removed. By contrast, in air the combustion will cease as soon as the heat is removed because the oxygen is diluted with nitrogen. A clear, flawless, transparent diamond is completely converted to carbon dioxide; any impurities will be left as ash. Heat generated from cutting a diamond will not ignite the diamond, and neither will

1590-463: A transition between graphite and diamond are well established theoretically and experimentally. The equilibrium pressure varies linearly with temperature, between 1.7  GPa at 0 K and 12 GPa at 5000 K (the diamond/graphite/liquid triple point ). However, the phases have a wide region about this line where they can coexist. At standard temperature and pressure , 20 °C (293 K) and 1 standard atmosphere (0.10 MPa),

1696-585: A very high refractive index and a relatively high optical dispersion . Most natural diamonds have ages between 1 billion and 3.5 billion years. Most were formed at depths between 150 and 250 kilometres (93 and 155 mi) in the Earth's mantle , although a few have come from as deep as 800 kilometres (500 mi). Under high pressure and temperature, carbon-containing fluids dissolved various minerals and replaced them with diamonds. Much more recently (hundreds to tens of million years ago), they were carried to

1802-467: A very linear trajectory which is explained by their high density. Diamond also reacts with fluorine gas above about 700 °C (1,292 °F). Diamond has a wide band gap of 5.5  eV corresponding to the deep ultraviolet wavelength of 225   nanometers. This means that pure diamond should transmit visible light and appear as a clear colorless crystal. Colors in diamond originate from lattice defects and impurities. The diamond crystal lattice

1908-425: A volcanic rock. There are many theories for its origin, including formation in a star, but no consensus. Diamond is the hardest material on the qualitative Mohs scale . To conduct the quantitative Vickers hardness test , samples of materials are struck with a pyramid of standardized dimensions using a known force – a diamond crystal is used for the pyramid to permit a wide range of materials to be tested. From

2014-449: Is 0.01% for nickel and even less for cobalt. Virtually any element can be introduced to diamond by ion implantation. Nitrogen is by far the most common impurity found in gem diamonds and is responsible for the yellow and brown color in diamonds. Boron is responsible for the blue color. Color in diamond has two additional sources: irradiation (usually by alpha particles), that causes the color in green diamonds, and plastic deformation of

2120-415: Is a solid form of pure carbon with its atoms arranged in a crystal. Solid carbon comes in different forms known as allotropes depending on the type of chemical bond. The two most common allotropes of pure carbon are diamond and graphite . In graphite, the bonds are sp orbital hybrids and the atoms form in planes, with each bound to three nearest neighbors, 120 degrees apart. In diamond, they are sp and

2226-546: Is a tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure , but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. They are also

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2332-420: Is aided by isotopic dating and modeling of the geological history. Then surveyors must go to the area and collect samples, looking for kimberlite fragments or indicator minerals . The latter have compositions that reflect the conditions where diamonds form, such as extreme melt depletion or high pressures in eclogites . However, indicator minerals can be misleading; a better approach is geothermobarometry , where

2438-627: Is also a version that the stone was acquired on behalf of Menshikov in the Netherlands . Sources from the times of the Russian Empire differ in the definition of the stone that topped the great imperial crowns of Russian emperors and empresses: some of them define it as a true ruby , a precious red corundum (“oriental ruby”, “yakhont”, “red yakhont”), and others define it as “lal”, that is, spinel or tourmaline (pink and red spinels and tourmalines were not yet distinguished at that time). Already in

2544-723: Is also indicative, but other materials have similar refractivity. Diamonds are extremely rare, with concentrations of at most parts per billion in source rock. Before the 20th century, most diamonds were found in alluvial deposits . Loose diamonds are also found along existing and ancient shorelines , where they tend to accumulate because of their size and density. Rarely, they have been found in glacial till (notably in Wisconsin and Indiana ), but these deposits are not of commercial quality. These types of deposit were derived from localized igneous intrusions through weathering and transport by wind or water . Most diamonds come from

2650-405: Is another mechanical property toughness , which is a material's ability to resist breakage from forceful impact. The toughness of natural diamond has been measured as 50–65  MPa ·m . This value is good compared to other ceramic materials, but poor compared to most engineering materials such as engineering alloys, which typically exhibit toughness over 80   MPa·m . As with any material,

2756-414: Is called diamond cubic . It is formed of unit cells (see the figure) stacked together. Although there are 18 atoms in the figure, each corner atom is shared by eight unit cells and each atom in the center of a face is shared by two, so there are a total of eight atoms per unit cell. The length of each side of the unit cell is denoted by a and is 3.567  angstroms . The nearest neighbor distance in

2862-402: Is exceptionally strong, and only atoms of nitrogen , boron , and hydrogen can be introduced into diamond during the growth at significant concentrations (up to atomic percents). Transition metals nickel and cobalt , which are commonly used for growth of synthetic diamond by high-pressure high-temperature techniques, have been detected in diamond as individual atoms; the maximum concentration

2968-419: Is formed of layers stacked in a repeating ABCABC ... pattern. Diamonds can also form an ABAB ... structure, which is known as hexagonal diamond or lonsdaleite , but this is far less common and is formed under different conditions from cubic carbon. Diamonds occur most often as euhedral or rounded octahedra and twinned octahedra known as macles . As diamond's crystal structure has a cubic arrangement of

3074-412: Is higher for flawless, pure crystals oriented to the <111> direction (along the longest diagonal of the cubic diamond lattice). Therefore, whereas it might be possible to scratch some diamonds with other materials, such as boron nitride , the hardest diamonds can only be scratched by other diamonds and nanocrystalline diamond aggregates . The hardness of diamond contributes to its suitability as

3180-404: Is hybrid rock with a chaotic mixture of small minerals and rock fragments ( clasts ) up to the size of watermelons. They are a mixture of xenocrysts and xenoliths (minerals and rocks carried up from the lower crust and mantle), pieces of surface rock, altered minerals such as serpentine , and new minerals that crystallized during the eruption. The texture varies with depth. The composition forms

3286-576: Is in terrible disorder ... money is not paid to anyone. God knows what will happen with finances. Everyone steals, as much as he can." Moving the court and several other institutions from St. Petersburg back to Moscow (1728) was painful for the "Northern Capital", as well as for the nobility forced to move with it, as Peter the Great had put much effort into developing St. Petersburg into a large and lively city. Peter II returned to St. Petersburg from time to time, but continued to lead an aimless life full of entertainment and distraction. He gradually fell under

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3392-647: Is in the form of micro/nanoscale wires or needles (~100–300   nanometers in diameter, micrometers long), they can be elastically stretched by as much as 9–10 percent tensile strain without failure, with a maximum local tensile stress of about 89–98 GPa , very close to the theoretical limit for this material. Other specialized applications also exist or are being developed, including use as semiconductors : some blue diamonds are natural semiconductors, in contrast to most diamonds, which are excellent electrical insulators . The conductivity and blue color originate from boron impurity. Boron substitutes for carbon atoms in

3498-477: Is one of the 4C's (color, clarity, cut and carat weight) that helps in identifying the quality of diamonds. The Gemological Institute of America (GIA) developed 11 clarity scales to decide the quality of a diamond for its sale value. The GIA clarity scale spans from Flawless (FL) to included (I) having internally flawless (IF), very, very slightly included (VVS), very slightly included (VS) and slightly included (SI) in between. Impurities in natural diamonds are due to

3604-797: Is partially oxidized. The oxidized surface can be reduced by heat treatment under hydrogen flow. That is to say, this heat treatment partially removes oxygen-containing functional groups. But diamonds (sp C) are unstable against high temperature (above about 400 °C (752 °F)) under atmospheric pressure. The structure gradually changes into sp C above this temperature. Thus, diamonds should be reduced below this temperature. At room temperature, diamonds do not react with any chemical reagents including strong acids and bases. In an atmosphere of pure oxygen, diamond has an ignition point that ranges from 690 °C (1,274 °F) to 840 °C (1,540 °F); smaller crystals tend to burn more easily. It increases in temperature from red to white heat and burns with

3710-765: Is possible to treat regular diamonds under a combination of high pressure and high temperature to produce diamonds that are harder than the diamonds used in hardness gauges. Diamonds cut glass, but this does not positively identify a diamond because other materials, such as quartz, also lie above glass on the Mohs scale and can also cut it. Diamonds can scratch other diamonds, but this can result in damage to one or both stones. Hardness tests are infrequently used in practical gemology because of their potentially destructive nature. The extreme hardness and high value of diamond means that gems are typically polished slowly, using painstaking traditional techniques and greater attention to detail than

3816-454: Is the case with most other gemstones; these tend to result in extremely flat, highly polished facets with exceptionally sharp facet edges. Diamonds also possess an extremely high refractive index and fairly high dispersion. Taken together, these factors affect the overall appearance of a polished diamond and most diamantaires still rely upon skilled use of a loupe (magnifying glass) to identify diamonds "by eye". Somewhat related to hardness

3922-595: The College of War . The coronation ceremony of the Empress took place on May 7. In the “Description of the Coronation of Her Majesty Empress Catherine Alekseevna” the stone is described as follows: In the whole of this crown only one colored stone was visible, that is, a straight oriental ruby or yakhont of very pure color, larger than a pigeon's egg, and therefore by far the most valuable of all rubies known to this day. By June 9

4028-731: The Earth's mantle , and most of this section discusses those diamonds. However, there are other sources. Some blocks of the crust, or terranes , have been buried deep enough as the crust thickened so they experienced ultra-high-pressure metamorphism . These have evenly distributed microdiamonds that show no sign of transport by magma. In addition, when meteorites strike the ground, the shock wave can produce high enough temperatures and pressures for microdiamonds and nanodiamonds to form. Impact-type microdiamonds can be used as an indicator of ancient impact craters. Popigai impact structure in Russia may have

4134-553: The New England area in New South Wales , Australia. These diamonds are generally small, perfect to semiperfect octahedra, and are used to polish other diamonds. Their hardness is associated with the crystal growth form, which is single-stage crystal growth. Most other diamonds show more evidence of multiple growth stages, which produce inclusions, flaws, and defect planes in the crystal lattice, all of which affect their hardness. It

4240-546: The Wawa belt of the Superior province in Canada and microdiamonds in the island arc of Japan are found in a type of rock called lamprophyre . Kimberlites can be found in narrow (1 to 4 meters) dikes and sills, and in pipes with diameters that range from about 75 m to 1.5 km. Fresh rock is dark bluish green to greenish gray, but after exposure rapidly turns brown and crumbles. It

4346-436: The lithosphere . Such depths occur below cratons in mantle keels , the thickest part of the lithosphere. These regions have high enough pressure and temperature to allow diamonds to form and they are not convecting, so diamonds can be stored for billions of years until a kimberlite eruption samples them. Host rocks in a mantle keel include harzburgite and lherzolite , two type of peridotite . The most dominant rock type in

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4452-523: The normal color range , and applies a grading scale from "D" (colorless) to "Z" (light yellow). Yellow diamonds of high color saturation or a different color, such as pink or blue, are called fancy colored diamonds and fall under a different grading scale. In 2008, the Wittelsbach Diamond , a 35.56-carat (7.112 g) blue diamond once belonging to the King of Spain, fetched over US$ 24 million at

4558-402: The upper mantle , peridotite is an igneous rock consisting mostly of the minerals olivine and pyroxene ; it is low in silica and high in magnesium . However, diamonds in peridotite rarely survive the trip to the surface. Another common source that does keep diamonds intact is eclogite , a metamorphic rock that typically forms from basalt as an oceanic plate plunges into the mantle at

4664-469: The 19th century, the definition “spinel ruby” was found in inventories, but only the examination of Academician Fersman reliably established that the largest of the seven historical stones of the Diamond Fund is indeed a spinel The Menshikov Ruby is mentioned in the historical novels The Hunt of Peter II by Yuri Vigor and The Dishonored Bride by Margarita Anisimkova  [ ru ] , as well as in

4770-404: The Diamond Fund catalogue in 1924, he estimated the net weight of spinel, excluding the pin, as approximately equal to 402 metric carats; later sources also cite the figure of 398.72 metric carats. The large red gemstone adorned several great imperial crowns of Russian emperors and empresses created in the 18th century. It is believed that it was one and the same stone that was used to decorate

4876-497: The Emperor's decisions. According to contemporaries, Ivan Dolgorukov lived a reckless and profligate lifestyle, leading Peter II to spend much time feasting, playing cards and enjoying the company of women. He soon became addicted to alcohol. The coronation of Peter II took place in Moscow on 9 January 1728, with the Emperor and a huge entourage. Still, he was disengaged from the affairs of state. Foreign witnesses proclaimed: "All of Russia

4982-511: The Tsar had disliked their father and even their grandmother, his own first wife, and young Peter in particular reminded him of his only son Alexei, whom the Tsar suspected of treachery. Therefore, from his childhood, the young and orphaned Peter was kept in the strictest seclusion. His earliest governesses were the wives of a tailor and a vintner from the Dutch settlement, while a sailor named Norman taught him

5088-462: The atoms form tetrahedra, with each bound to four nearest neighbors. Tetrahedra are rigid, the bonds are strong, and, of all known substances, diamond has the greatest number of atoms per unit volume, which is why it is both the hardest and the least compressible . It also has a high density, ranging from 3150 to 3530 kilograms per cubic metre (over three times the density of water) in natural diamonds and 3520 kg/m in pure diamond. In graphite,

5194-420: The atoms, they have many facets that belong to a cube , octahedron, rhombicosidodecahedron , tetrakis hexahedron , or disdyakis dodecahedron . The crystals can have rounded-off and unexpressive edges and can be elongated. Diamonds (especially those with rounded crystal faces) are commonly found coated in nyf , an opaque gum-like skin. Some diamonds contain opaque fibers. They are referred to as opaque if

5300-446: The back of his sleigh. The next day doctors diagnosed smallpox . The Dolgorukovs attempted to get the emperor to sign a testament naming Ekaterina as his heir, but they were not allowed into the dying emperor’s quarters: Peter II was already unconscious. In his delirium, he ordered horses so that he could visit his sister Natalya (who had died in 1728). A few minutes later, he died. Emperor Peter II died as dawn broke on 30 January 1730 –

5406-410: The bonds between nearest neighbors are even stronger, but the bonds between parallel adjacent planes are weak, so the planes easily slip past each other. Thus, graphite is much softer than diamond. However, the stronger bonds make graphite less flammable. Diamonds have been adopted for many uses because of the material's exceptional physical characteristics. It has the highest thermal conductivity and

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5512-461: The boy's teachers with the vice-chancellor, Count Ostermann . The program of education that Ostermann compiled included history, geography, mathematics, and foreign languages, but the overall education of the future emperor remained shallow and left much to be desired. Peter himself did not display much interest in study; his favorite occupations were hunting and feasting. By the time Catherine I died in 1727, it had become clear to those in power that

5618-507: The carbon source is more likely carbonate rocks and organic carbon in sediments, rather than coal. Diamonds are far from evenly distributed over the Earth. A rule of thumb known as Clifford's rule states that they are almost always found in kimberlites on the oldest part of cratons , the stable cores of continents with typical ages of 2.5   billion years or more. However, there are exceptions. The Argyle diamond mine in Australia ,

5724-436: The coloration, while pure or nearly pure diamonds are transparent and colorless. Most diamond impurities replace a carbon atom in the crystal lattice , known as a carbon flaw . The most common impurity, nitrogen, causes a slight to intense yellow coloration depending upon the type and concentration of nitrogen present. The Gemological Institute of America (GIA) classifies low saturation yellow and brown diamonds as diamonds in

5830-497: The compositions of minerals are analyzed as if they were in equilibrium with mantle minerals. Finding kimberlites requires persistence, and only a small fraction contain diamonds that are commercially viable. The only major discoveries since about 1980 have been in Canada. Since existing mines have lifetimes of as little as 25 years, there could be a shortage of new diamonds in the future. Diamonds are dated by analyzing inclusions using

5936-451: The cross a red lal worth 60 thousand rubles”. Soon after the coronation, it was apparently dismantled - it is reliably known that this was done with the orb . For the coronation ceremony of Catherine II in 1762, it was necessary to make the great imperial crown and orb again (the scepter was traditionally taken from the Workshop and Armory Chamber). The goldsmith Georg Friedrich Eckart and

6042-508: The crown had already been dismantled, and its frame was transferred to the Workshop and Armory Chamber . The Russian State Archive of Ancient Acts  [ ru ] (RSAAA) contains several drawings that, according to most experts, depict the crown of Catherine I, despite the fact that they are among the documents on the coronation of Peter II , since according to textual descriptions, the crown of Peter II looked different. The red stone from

6148-531: The crown of Anna Ioannovna and from the Great Imperial Crown, are too large to be the Spathari’s stone, since it weighed a little over eleven zolotniks , i.e. only slightly more than 47 grams or 240 carats . Spathari's Lal may have once topped the crown of Anna Ioannovna, but in that case he was removed from the crown in 1732 and “taken into the cabinet”, as Alexei Malinovsky originally pointed out. There

6254-680: The day scheduled for his marriage to Ekaterina Dolgorukova. He is buried in the Cathedral of the Archangel located at the Moscow Kremlin and was the only post-Petrine Russian monarch given that honor; along with Ivan VI (who was murdered and buried in the fortress of Shlisselburg ), he is the only post-Petrine monarch not buried in the Peter and Paul Cathedral in Saint Petersburg. With Peter's death,

6360-598: The decay of radioactive isotopes. Depending on the elemental abundances, one can look at the decay of rubidium to strontium , samarium to neodymium , uranium to lead , argon-40 to argon-39 , or rhenium to osmium . Those found in kimberlites have ages ranging from 1 to 3.5 billion years , and there can be multiple ages in the same kimberlite, indicating multiple episodes of diamond formation. The kimberlites themselves are much younger. Most of them have ages between tens of millions and 300 million years old, although there are some older exceptions (Argyle, Premier and Wawa). Thus,

6466-470: The diamond crystal lattice. Plastic deformation is the cause of color in some brown and perhaps pink and red diamonds. In order of increasing rarity, yellow diamond is followed by brown, colorless, then by blue, green, black, pink, orange, purple, and red. "Black", or carbonado , diamonds are not truly black, but rather contain numerous dark inclusions that give the gems their dark appearance. Colored diamonds contain impurities or structural defects that cause

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6572-501: The diamond lattice is 1.732 a /4 where a is the lattice constant, usually given in Angstrøms as a = 3.567 Å, which is 0.3567 nm. A diamond cubic lattice can be thought of as two interpenetrating face-centered cubic lattices with one displaced by 1 ⁄ 4 of the diagonal along a cubic cell, or as one lattice with two atoms associated with each lattice point. Viewed from a <1 1 1> crystallographic direction , it

6678-415: The diamond lattice, donating a hole into the valence band . Substantial conductivity is commonly observed in nominally undoped diamond grown by chemical vapor deposition . This conductivity is associated with hydrogen -related species adsorbed at the surface, and it can be removed by annealing or other surface treatments. Thin needles of diamond can be made to vary their electronic band gap from

6784-407: The diamonds' surface cannot be wet by water, but can be easily wet and stuck by oil. This property can be utilized to extract diamonds using oil when making synthetic diamonds. However, when diamond surfaces are chemically modified with certain ions, they are expected to become so hydrophilic that they can stabilize multiple layers of water ice at human body temperature . The surface of diamonds

6890-499: The efforts of Menshikov, the court named Peter as Catherine's heir apparent, even though Catherine had two daughters of her own. The relevant documentation also specified the betrothal of Peter to Menshikov's daughter Maria . After Catherine's death in May 1727 and the proclamation of the 11-year-old Peter II as emperor, Menshikov took the young autocrat into his own house on Vasilievsky Island and had full control over all of his actions. For

6996-449: The fibers grow from a clear substrate or fibrous if they occupy the entire crystal. Their colors range from yellow to green or gray, sometimes with cloud-like white to gray impurities. Their most common shape is cuboidal, but they can also form octahedra, dodecahedra, macles, or combined shapes. The structure is the result of numerous impurities with sizes between 1 and 5 microns. These diamonds probably formed in kimberlite magma and sampled

7102-408: The hardness and transparency of diamond, are the reasons that diamond anvil cells are the main tool for high pressure experiments. These anvils have reached pressures of 600 GPa . Much higher pressures may be possible with nanocrystalline diamonds. Usually, attempting to deform bulk diamond crystal by tension or bending results in brittle fracture. However, when single crystalline diamond

7208-455: The highest sound velocity. It has low adhesion and friction, and its coefficient of thermal expansion is extremely low. Its optical transparency extends from the far infrared to the deep ultraviolet and it has high optical dispersion . It also has high electrical resistance. It is chemically inert, not reacting with most corrosive substances, and has excellent biological compatibility. The equilibrium pressure and temperature conditions for

7314-479: The imperial administration – officials did not dare to assume responsibility for important decisions. The Russian fleet became neglected, but Peter II showed no interest in the matter. Peter tightened serfdom by banning serfs from volunteering for military service and thus escaping their status. With the fall of Menshikov and related court intrigues, the Emperor's main favorites became Prince Aleksey Dolgorukov and his son Ivan, who maintained great influence over

7420-436: The imperial crown was shown to him and several others by secret cabinet secretary Alexei Makarov , and at that time there was already “a very expensive and incredibly large ruby , almost a finger's length” on the top. This stone was received from Prince Menshikov; in 1727 Menshikov testified in a case about his financial misconduct, that for this Peter I had allowed him, by oral decree, not to return 10 thousand rubles taken from

7526-401: The income books, because the head of the Department of Siberian Affairs in 1705 was Prince Fyodor Romodanovsky. In 1724, Catherine I was crowned. After the crown made for the coronation was brought to Moscow , the original top in the form of a golden monde studded with diamonds was replaced with a large red stone. Friedrich Wilhelm von Bergholz wrote in his diary that on March 30, 1724,

7632-460: The influence of Ostermann and the Dolgorukovs , Peter – long sick of Menshikov's wardship – stripped him of his rank (September 1727) and exiled him to Siberia . The Emperor also dissolved his engagement with Menshikov's daughter. The senate , the privy council and the guards took the oath of allegiance forthwith. At this time, German mathematician Christian Goldbach was appointed tutor to

7738-614: The inventory of 1865 it was already listed as “an irregularly shaped spinel ruby, worth 100,000 rubles”. Since 1967, the crown, and along with it the historical spinel, has been an exhibit of the Diamond Fund . It is a common misconception that the Spinel of the Great Imperial Crown is the stone that Nikolai Spathari bought in Beijing during his embassy to the Qing Empire . Originally, it refer to

7844-423: The kimberlites formed independently of the diamonds and served only to transport them to the surface. Kimberlites are also much younger than the cratons they have erupted through. The reason for the lack of older kimberlites is unknown, but it suggests there was some change in mantle chemistry or tectonics. No kimberlite has erupted in human history. Most gem-quality diamonds come from depths of 150–250 km in

7950-467: The largest producer of diamonds by weight in the world, is located in a mobile belt , also known as an orogenic belt , a weaker zone surrounding the central craton that has undergone compressional tectonics. Instead of kimberlite , the host rock is lamproite . Lamproites with diamonds that are not economically viable are also found in the United States, India, and Australia. In addition, diamonds in

8056-467: The macroscopic geometry of a diamond contributes to its resistance to breakage. Diamond has a cleavage plane and is therefore more fragile in some orientations than others. Diamond cutters use this attribute to cleave some stones before faceting them. "Impact toughness" is one of the main indexes to measure the quality of synthetic industrial diamonds. Diamond has compressive yield strength of 130–140   GPa. This exceptionally high value, along with

8162-591: The melting point of diamond increases slowly with increasing pressure; but at pressures of hundreds of GPa, it decreases. At high pressures, silicon and germanium have a BC8 body-centered cubic crystal structure, and a similar structure is predicted for carbon at high pressures. At 0 K , the transition is predicted to occur at 1100 GPa . Results published in an article in the scientific journal Nature Physics in 2010 suggest that, at ultra-high pressures and temperatures (about 10 million atmospheres or 1 TPa and 50,000 °C), diamond melts into

8268-579: The melts to carry diamonds to the surface before they dissolve. Kimberlite pipes can be difficult to find. They weather quickly (within a few years after exposure) and tend to have lower topographic relief than surrounding rock. If they are visible in outcrops, the diamonds are never visible because they are so rare. In any case, kimberlites are often covered with vegetation, sediments, soils, or lakes. In modern searches, geophysical methods such as aeromagnetic surveys , electrical resistivity , and gravimetry , help identify promising regions to explore. This

8374-457: The next crown after the previous one was dismantled. The first information about it dates back to 1702, when the retired Nerchinsk captain of fifty Yan Istopnikov, being at the head of the state caravan in China , exchanged “a red lal stone, weighing 19 zolotniks and half a zolotnik” for 8,000 liang . Prince Alexander Menshikov , in his letter from Kiev dated May 12, 1705, gave instructions to buy

8480-469: The normal 5.6 eV to near zero by selective mechanical deformation. High-purity diamond wafers 5 cm in diameter exhibit perfect resistance in one direction and perfect conductance in the other, creating the possibility of using them for quantum data storage. The material contains only 3 parts per million of nitrogen. The diamond was grown on a stepped substrate, which eliminated cracking. Diamonds are naturally lipophilic and hydrophobic , which means

8586-515: The only grandson of Peter the Great could not be kept from his inheritance much longer. The majority of Russians and three-quarters of the nobility (especially the old-established nobility) were on his side, while the Holy Roman Emperor Charles VI (the husband of Peter's mother's elder sister, Elisabeth Christine of Brunswick-Wolfenbüttel ) persistently urged Peter's claims through the imperial ambassador at Saint Petersburg . Through

8692-620: The presence of natural minerals and oxides. The clarity scale grades the diamond based on the color, size, location of impurity and quantity of clarity visible under 10x magnification. Inclusions in diamond can be extracted by optical methods. The process is to take pre-enhancement images, identifying the inclusion removal part and finally removing the diamond facets and noises. Between 25% and 35% of natural diamonds exhibit some degree of fluorescence when examined under invisible long-wave ultraviolet light or higher energy radiation sources such as X-rays and lasers. Incandescent lighting will not cause

8798-476: The reason that diamond anvil cells can subject materials to pressures found deep in the Earth. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen ). Small numbers of defects or impurities (about one per million of lattice atoms) can color a diamond blue (boron), yellow (nitrogen), brown (defects), green (radiation exposure), purple, pink, orange, or red. Diamond also has

8904-454: The rudiments of navigation. When he grew older, however, Peter was placed under the care of a Hungarian noble, Janos (Ivan) Zeikin (Zékány), who seems to have been a conscientious teacher. Peter the Great died in 1725 and was succeeded by his second wife, Catherine I , a woman of low birth. The powerful minister Aleksander Danilovich Menshikov , who had aided in Catherine's accession, replaced

9010-482: The same one that crowned the crown of Catherine I. From February 1728 to the end of December 1729, the crown of Peter II was kept in the Workshop Chamber. The last mention of the crown dates from December 31, 1729, when it was issued from the chamber to the hof-intendant Peter Moshkov in preparation for the emperor's wedding. In early January 1730 came Osterman's decree “to make for the marriage of His Imperial Majesty

9116-453: The short story The Passion for Menshikov by Mikhail Kheifets , and plays an important role in the plot of the novel The Fourth Ruby from the children's fantasy series Section 13 by the American writer James R. Hannibal. Diamond Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic . Diamond as a form of carbon

9222-529: The size of the resulting indentation, a Vickers hardness value for the material can be determined. Diamond's great hardness relative to other materials has been known since antiquity, and is the source of its name. This does not mean that it is infinitely hard, indestructible, or unscratchable. Indeed, diamonds can be scratched by other diamonds and worn down over time even by softer materials, such as vinyl phonograph records . Diamond hardness depends on its purity, crystalline perfection, and orientation: hardness

9328-419: The stable phase of carbon is graphite, but diamond is metastable and its rate of conversion to graphite is negligible. However, at temperatures above about 4500 K , diamond rapidly converts to graphite. Rapid conversion of graphite to diamond requires pressures well above the equilibrium line: at 2000 K , a pressure of 35 GPa is needed. Above the graphite–diamond–liquid carbon triple point,

9434-649: The stone from Istopnikov, reimbursing him for the money spent and giving him a bonus of 1,000 rubles . On October 5, 1705, Istopnikov gave the stone to the Department of Siberian Affairs and received 9,000 rubles from the money of the Department of Siberian Affairs and the Ingermanland Chancellery , but the stone was “not in the record” in the income books for 1705 and 1706. While already under investigation for embezzlement, Prince Matvei Gagarin  [ ru ] testified that in 1705, Yan Istopnikov “revealed

9540-511: The stone that had already crowned the crowns of Catherine I , Peter II and Elizabeth Petrovna . Emperor Paul I did not order a new crown for his coronation, but used his mother’s, and since then the Great Imperial Crown of Catherine II has become the hereditary regalia of the Romanovs . In 1838, in the inventory of crown items, the stone under the cross was called a “large ruby”, and in

9646-484: The stone that tops Anna Ioannovna's crown. Back in 1807, Alexei Malinovsky  [ ru ] , who mistakenly believed that this crown was made for the coronation of Catherine I and was subsequently used at the coronations of Peter II and Anna Ioannovna, wrote about it: According to the expense books of the Chamber Archive, the crown of Empress Catherine I contained a greatest size and excellent quality lal, which

9752-524: The surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites . Synthetic diamonds can be grown from high-purity carbon under high pressures and temperatures or from hydrocarbon gases by chemical vapor deposition (CVD). Imitation diamonds can also be made out of materials such as cubic zirconia and silicon carbide . Natural, synthetic, and imitation diamonds are most commonly distinguished using optical techniques or thermal conductivity measurements. Diamond

9858-498: The thorough-going influence of the Dolgorukovs, and became smitten with the 18-year-old beauty Ekaterina Alekseyevna Dolgorukova . The Dolgorukov family schemed to tie themselves to the imperial bloodline, and persuaded Peter to become engaged to marry Ekaterina. However, it soon became clear that the young monarch had no interest in his fiancee, perhaps influenced by his aunt Elizabeth Petrovna , who did not like Ekaterina. Planning for

9964-567: The top of the crown returned to Prince Menshikov. Boris Kurakin later wrote about Menshikov: “And he had a particularly famous thing - a red yakhont, of great value, which, due to its size, weight and color, was considered unique in Europe ”. After Menshikov was arrested on September 8, 1727, as a result of the work of the investigative commission of the Supreme Privy Council , the gemstone was confiscated. On September 11, Pyotr Moshkov announced

10070-454: The volatiles. Diamonds can also form polycrystalline aggregates. There have been attempts to classify them into groups with names such as boart , ballas , stewartite, and framesite, but there is no widely accepted set of criteria. Carbonado, a type in which the diamond grains were sintered (fused without melting by the application of heat and pressure), is black in color and tougher than single crystal diamond. It has never been observed in

10176-435: The wedding went forward regardless, set to take place on 30 January  [ O.S. 19 January]  1730. "Peter II has not reached the age when a person's personality has already shaped," historian Mykola Kostomarov wrote. "While contemporaries praised his natural intelligence and good heart, they only hoped for that good to happen in the future. However, his behavior did not give chances to hope that he would be

10282-430: The world's largest diamond deposit, estimated at trillions of carats, and formed by an asteroid impact. A common misconception is that diamonds form from highly compressed coal . Coal is formed from buried prehistoric plants, and most diamonds that have been dated are far older than the first land plants . It is possible that diamonds can form from coal in subduction zones , but diamonds formed in this way are rare, and

10388-465: The young Peter II to take over from Andrey Osterman , whom Menshikov had appointed. Peter II was quick-witted, but apparently a stubborn and wayward boy, much like his grandfather. Despite these similarities, the emperor had no desire to learn to rule, unlike Peter the Great . His young age meant that he could not adequately manage public affairs, and he almost never appeared at the Supreme Privy Council . This led to frustration among his subjects and in

10494-462: The “diamondsmith” Jeremie Pauzie took part in the creation of the crown. The latter was tasked with framing the crown with stones. The “Description of the diamonds , large lal and pearls that are in the crown, number, weight and price with all expenses” from September 22, 1762 has been preserved. The crown contained 58 “the largest diamonds”, 4,878 diamonds “of various sizes”, 75 “large pearls” and 1 “large lal” weighing 389½ carats – apparently, again

10600-407: The “large red lal stone” at a meeting of the Supreme Privy Council and handed it over to Vice-Chancellor Baron Andrei Osterman “for delivery to His Imperial Majesty”. Thus the stone ended up in the state treasury. With the rise to power of Peter II in May 1727, the need arose to create new regalia for the coronation ceremony. Since the crown of Catherine I had long been dismantled by this time, at

10706-561: Was also influenced by favorites like Prince Aleksey Dolgorukov , leading to a neglect of state affairs and the tightening of serfdom . Peter's reign was marked by disengagement, disorder, and indulgence. He was engaged to Ekaterina Dolgorukova , but died suddenly of smallpox before the marriage, thus making him the last male agnatic member of the House of Romanov . Peter was born in Saint Petersburg on 23 ( O.S. 12 ) October 1715. His father

10812-688: Was generally accepted. In the 20th century, the Soviet researcher Alexander Fersman expressed doubt that it was possible to establish which of the two surviving precious tops of the Russian imperial crowns is the Spathari's stone and which was the Menshikov's stone, but since the mid-20th century the Spathari's Lal  [ ru ] has been identified with the Spinel of the Great Imperial Crown. In fact, both stones, from

10918-428: Was made by a team of craftsmen led by Johann Heinrich Zart. They were mostly foreign jewellers, but they also included a group of resident Russian craftsmen headed by Samson Larionov. After the coronation, the regalia were put on public display. An eyewitness of this, Yakov Markevich  [ ru ] , wrote about the crown in his diary that it had “the largest diamond at the bottom worth 25 thousand rubles, and under

11024-574: Was taken into the cabinet by order of Empress Anna Ioannovna. This lal is the same one that was bought in 1676 for a very significant sum at that time, by order of Tsar Alexei Mikhailovich , in Beijing by Nikolai Spathari, the Russian ambassador to the Chinese Bogda Khan Kangxi . Various publications in pre-revolutionary Russia linked this statement with the stone that has been under the cross of Anna Ioannovna's crown since 1732; this version

11130-498: Was the only living son of Peter the Great . His mother was well-connected to European royalty, and through her, Peter was a first cousin of Empress Maria Theresa of Austria. Peter's mother died when he was only ten days old. His father, the tsarevich Alexei, accused of treason by his own father, Peter the Great , died in prison in 1718. So three-year-old Peter and his four-year-old sister, Natalya , became orphans. Their grandfather showed no interest in their upbringing or education:

11236-545: Was ultimately used, but be that as it may, the original top was subsequently replaced by a large, but relatively cheap stone, valued at only a thousand rubles. It serves as the top of the crown of Anna Ioannovna to this day and, as a modern examination has established, is a red tourmaline. Worth 60 thousand rubles, the lal appears again in the Great Crown of Elizabeth Petrovna , made for her coronation in St. Petersburg in 1742. This crown

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