156-734: The Pigot Diamond , also sometimes called the Pigott Diamond , the Lottery Diamond , or the Great Lottery Diamond , was a large diamond that originated in India in the 18th century and was brought to England where at the time it was the largest diamond in Europe. It remained in Europe for half a century, changing hands several times until it was sold to the ruler of Egypt in the 1820s. What happened to it after that
312-472: A Bronze Age bridge were found on the south River Thames foreshore, upstream from Vauxhall Bridge . Two of the timbers were radiocarbon dated to 1750–1285 BC. In 2010, foundations of a large timber structure, dated to 4800–4500 BC, were found on the Thames' south foreshore downstream from Vauxhall Bridge. Both structures are on the south bank of the Thames, where the now-underground River Effra flows into
468-659: A subduction zone . London London is the capital and largest city of both England and the United Kingdom , with a population of 8,866,180 in 2022. The wider metropolitan area is the largest in Western Europe , with a population of 14.9 million. London stands on the River Thames in southeast England, at the head of a 50-mile (80 km) estuary down to the North Sea , and has been
624-635: A "relatively" complete dictionary of gemology lists the Queen of Albania Diamond as a 49.03 carats (9.806 g) pear-shaped diamond, probably from South Africa , owned by Queen Geraldine of Albania until she sold it in London in 1960. It then states that this diamond "is believed...to be the same as the Pigott Diamond." Although the size is similar, the shape is different making this unlikely. The November 1804 edition of The Gentleman's Magazine ,
780-491: 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
936-568: A London periodical, published that the Pigot diamond was purchased by or for Madam Bonaparte, Napoleon's mother, for a necklace. In 1840, a British scholastic book said the Pigot diamond, after having been sold to Mohammed Ali, somehow came to be an ornament on Bonaparte's sword of state and in 1840 was in the possession of the King of France . This is unlikely since the sale to Ali did not take place until after Bonaparte's death. Another famous diamond,
1092-453: 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
1248-727: 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
1404-452: 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
1560-458: A fine, oval brilliant , and had an official recorded weight of 47.38 carats (9.476 g). The cutting is said to have taken two years and cost £3,000. The size of the rough stone is estimated to have been around 100 carats (20 g). At the time, it was the largest diamond in England. It has been characterised as having a large table (the largest central facet of the crown) and girdle , but it
1716-480: 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
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#17327838093801872-542: A larger area, similar in size to Greater London, although some outer districts are excluded and some just outside included. The Greater London boundary has been aligned to the M25 motorway in places. Further urban expansion is now prevented by the Metropolitan Green Belt , although the built-up area extends beyond the boundary in places, producing a separately defined Greater London Urban Area . Beyond this
2028-569: A major settlement for nearly 2,000 years. Its ancient core and financial centre , the City of London , was founded by the Romans as Londinium and has retained its medieval boundaries. The City of Westminster , to the west of the City of London, has been the centuries-long host of the national government and parliament . London grew rapidly in the 19th century , becoming the world's largest city at
2184-461: A market where its worth might not be sufficiently valued, where the charms of the fair needed not such ornaments, and whose sparkling eyes outshone all the diamonds of Golkonda . In any other county, the Pigot diamond would be sought as a distinction, where superior beauty was more rarely to be found. In 1804, it was offered for sale to Napoleon Bonaparte , who was just made Emperor of the French by
2340-475: 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
2496-403: 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
2652-403: A population density of 802 per acre (325 per hectare). In addition to the growing number of stores selling goods, such as Harding, Howell & Co. —one of the first department stores —located on Pall Mall , the streets had scores of street sellers . London's overcrowded conditions led to cholera epidemics, claiming 14,000 lives in 1848, and 6,000 in 1866. Rising traffic congestion led to
2808-573: A population of 7,172,036 in 2001 and a population density of 11,760 inhabitants per square mile (4,542/km ). The extended area known as the London Metropolitan Region or the London Metropolitan Agglomeration, comprises a total area of 3,236 square miles (8,382 km ) has a population of 13,709,000 and a population density of 3,900 inhabitants per square mile (1,510/km ). Modern London stands on
2964-554: 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
3120-532: A strong influence on world art , entertainment, fashion , commerce, finance, education , healthcare , media , science, technology, tourism , transport , and communications. Despite a post- Brexit exodus of stock listings from the London Stock Exchange , London remains a European economic powerhouse, and one of the world's major financial centres . It hosts Europe's largest concentration of higher education institutions , some of which are
3276-551: A temperate oceanic climate ( Köppen : Cfb ). Rainfall records have been kept in the city since at least 1697, when records began at Kew . At Kew, the most rainfall in one month is 7.4 inches (189 mm) in November 1755 and the least is 0 inches (0 mm) in both December 1788 and July 1800. Mile End also had 0 inches (0 mm) in April 1893. The wettest year on record is 1903, with a total fall of 38.1 inches (969 mm) and
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#17327838093803432-463: 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),
3588-467: 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
3744-425: 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
3900-449: 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
4056-644: Is 1,049.8 millibars (31.00 inHg) on 20 January 2020. Summers are generally warm, sometimes hot. London's average July high is 23.5 °C (74.3 °F). On average each year, London experiences 31 days above 25 °C (77.0 °F) and 4.2 days above 30.0 °C (86.0 °F). During the 2003 European heat wave , prolonged heat led to hundreds of heat-related deaths. A previous spell of 15 consecutive days above 32.2 °C (90.0 °F) in England in 1976 also caused many heat related deaths. A previous temperature of 37.8 °C (100.0 °F) in August 1911 at
4212-415: 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
4368-512: Is agreed that the name came into these languages from Common Brythonic ; recent work tends to reconstruct the lost Celtic form of the name as * Londonjon or something similar. This was then adapted into Latin as Londinium and borrowed into Old English. Until 1889, the name "London" applied officially only to the City of London , but since then it has also referred to the County of London and to Greater London . In 1993, remains of
4524-420: 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
4680-728: 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
4836-405: 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,
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4992-414: 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
5148-402: 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
5304-419: 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
5460-545: Is formed of two tiers: a citywide, strategic tier and a local tier. Citywide administration is coordinated by the Greater London Authority (GLA), while local administration is carried out by 33 smaller authorities. The GLA consists of two elected components: the mayor of London , who has executive powers , and the London Assembly , which scrutinises the mayor's decisions and can accept or reject
5616-707: Is headquartered in Thames House on the north bank of the River Thames and the foreign intelligence service ( MI6 ) is headquartered in the SIS Building on the south bank. Crime rates vary widely across different areas of London. Crime figures are made available nationally at Local Authority and Ward level. In 2015, there were 118 homicides, a 25.5% increase over 2014. Recorded crime has been rising in London, notably violent crime and murder by stabbing and other means have risen. There were 50 murders from
5772-592: Is held by an independent . The ministerial post of minister for London was created in 1994, however as of 2024, the post has been vacant. Policing in Greater London, with the exception of the City of London , is provided by the Metropolitan Police ("The Met"), overseen by the mayor through the Mayor's Office for Policing and Crime (MOPAC). The Met is also referred to as Scotland Yard after
5928-412: 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
6084-404: 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
6240-437: Is implausible. Since Ali Pasha was executed in 1822, he could not have purchased the diamond and the association to him is based on confusion of his name, Ali Pasha of Tepelena, with the actual purchaser, Mohammed Ali Pasha. There are also sources that say the confusion is in the opposite direction and Ali Pasha of Tepelena actually bought the diamond. It has also been suggested that the diamond passed from Egypt to Turkey and
6396-647: 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
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6552-564: Is known as London . It is the capital of the United Kingdom and of England by convention rather than statute. The capital of England was moved to London from Winchester as the Palace of Westminster developed in the 12th and 13th centuries to become the permanent location of the royal court , and thus the political capital of the nation. Greater London encompasses a total area of 611 square miles (1,583 km ) an area which had
6708-758: Is now exhibited as the Spoonmaker's Diamond ( Turkish : Kaşıkçı Elması ), the most valuable single exhibit of the Imperial Treasury exhibitions at the Topkapi Palace Museum. However, the weight of the Spoonmaker's Diamond, 86 carats (17.2 g), is much larger than that of the Pigot Diamond (47.38 carats (9.476 g)), and it is of a different shape, precluding them from being the same stones. This story survives because
6864-477: 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
7020-797: 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
7176-769: 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
7332-802: Is relatively shallow in depth giving it poor brilliance . On Pigot's death in 1777, he bequeathed it to his brothers, Robert (1721–1796), who commanded the left flank of the British forces at the Battle of Bunker Hill and Hugh (1722–1792), Commander-in-Chief of the West Indies fleet of the Royal Navy , and his widowed sister Margaret, the wife of Thomas Fisher. Upon Robert's death in 1796, his share passed to his son George Pigot . Upon Hugh's death in 1792, his share passed to his widow Frances and their five children. The joint owners attempted to sell
7488-452: 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 the reason that diamond anvil cells can subject materials to pressures found deep in
7644-454: 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
7800-523: Is the vast London commuter belt . Greater London is split for some purposes into Inner London and Outer London , and by the River Thames into North and South , with an informal central London area. The coordinates of the nominal centre of London, traditionally the original Eleanor Cross at Charing Cross near the junction of Trafalgar Square and Whitehall , are about 51°30′26″N 00°07′39″W / 51.50722°N 0.12750°W / 51.50722; -0.12750 . Within London, both
7956-659: Is unknown, inspiring a two-century mystery. The Pigot Diamond was obtained by George Pigot during his term as British governor of Madras , the capital city of the Indian state of Tamil Nadu for the East India Company . He may have received it from an Indian prince in 1763. This may have been the Rajah of Tanjore as Pigot had told the directors of the East India Company that he had received presents from
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#17327838093808112-517: The 2012 Summer Olympics . London is an ancient name, attested in the first century AD, usually in the Latinised form Londinium . Modern scientific analyses of the name must account for the origins of the different forms found in early sources: Latin (usually Londinium ), Old English (usually Lunden ), and Welsh (usually Llundein ), with reference to the known developments over time of sounds in those different languages. It
8268-540: The Black Death in the mid-14th century, London lost nearly a third of its population. London was the focus of the Peasants' Revolt in 1381. London was a centre of England's Jewish population before their expulsion by Edward I in 1290. Violence against Jews occurred in 1190, when it was rumoured that the new king had ordered their massacre after they had presented themselves at his coronation. In 1264 during
8424-533: The Canary Wharf development. This was born out of London's increasing role as an international financial centre in the 1980s. Located about 2 miles (3 km) east of central London, the Thames Barrier was completed in the 1980s to protect London against tidal surges from the North Sea . The Greater London Council was abolished in 1986, leaving London with no central administration until 2000 and
8580-672: The Corn Laws in 1846 was specifically aimed at weakening Dutch economic power. London then overtook Amsterdam as the leading international financial centre. With the onset of the Industrial Revolution in Britain, an unprecedented growth in urbanisation took place, and the number of High Streets (the primary street for retail in Britain) rapidly grew. London was the world's largest city from about 1831 to 1925 , with
8736-739: 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
8892-525: The French Senate . Rundell and Bridge thought this was an opportunity to interest Napoleon in the diamond. Since the ephemeral Peace of Amiens with England ended and France and England were again in conflict, the diamond had to be smuggled into France. It arrived in Paris after being brought through Holland by a man named Liebart, and was then offered to Napoleon by Laffitt & Co. Napoleon declined
9048-568: The Georgian era , new districts such as Mayfair were formed in the west; new bridges over the Thames encouraged development in South London . In the east, the Port of London expanded downstream. London's development as an international financial centre matured for much of the 18th century. In 1762, George III acquired Buckingham House , which was enlarged over the next 75 years. During
9204-584: The King's Road , Chelsea and Carnaby Street . The role of trendsetter revived in the punk era. In 1965 London's political boundaries were expanded in response to the growth of the urban area and a new Greater London Council was created. During The Troubles in Northern Ireland, London was hit from 1973 by bomb attacks by the Provisional Irish Republican Army . These attacks lasted for two decades, starting with
9360-627: The London Ambulance Service (LAS) NHS Trust , the largest free-at-the-point-of-use emergency ambulance service in the world. The London Air Ambulance charity operates in conjunction with the LAS where required. Her Majesty's Coastguard and the Royal National Lifeboat Institution operate on the River Thames , which is under the jurisdiction of the Port of London Authority from Teddington Lock to
9516-714: The Mediterranean was normally through Antwerp and over the Alps ; any ships passing through the Strait of Gibraltar to or from England were likely to be Italian or Ragusan . The reopening of the Netherlands to English shipping in January 1565 spurred a burst of commercial activity. The Royal Exchange was founded. Mercantilism grew and monopoly traders such as the East India Company were founded as trade expanded to
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#17327838093809672-566: 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
9828-613: The New Model Army entered London in 1647, and they were levelled by Parliament the same year. London was plagued by disease in the early 17th century, culminating in the Great Plague of 1665–1666, which killed up to 100,000 people, or a fifth of the population. The Great Fire of London broke out in 1666 in Pudding Lane in the city and quickly swept through the wooden buildings. Rebuilding took over ten years and
9984-564: The New World . London became the main North Sea port, with migrants arriving from England and abroad. The population rose from about 50,000 in 1530 to about 225,000 in 1605. In the 16th century, William Shakespeare and his contemporaries lived in London during English Renaissance theatre . Shakespeare's Globe Theatre was constructed in 1599 in Southwark . Stage performances came to a halt in London when Puritan authorities shut down
10140-612: The Old Bailey bombing . Racial inequality was highlighted by the 1981 Brixton riot . Greater London's population declined in the decades after the Second World War, from an estimated peak of 8.6 million in 1939 to around 6.8 million in the 1980s. The principal ports for London moved downstream to Felixstowe and Tilbury , with the London Docklands area becoming a focus for regeneration, including
10296-563: The Pitt Diamond , that also originated in India before being acquired by an Englishman ( Thomas Pitt ), was sold to French royalty and eventually was mounted to the pommel of Napoleon's sword. In an 1862 publication, the diamond's history was accurately recounted to the possession of Rundell & Bridge, but said it then went to a Portuguese Prince. A 1928 write-up said the diamond was sold by Rundell & Bridge in 1818 to "Ali Pasha,
10452-662: The Second Barons' War , Simon de Montfort 's rebels killed 500 Jews while attempting to seize records of debts. During the Tudor period , the Reformation produced a gradual shift to Protestantism . Much of London property passed from church to private ownership, which accelerated trade and business in the city. In 1475, the Hanseatic League set up a main trading base ( kontor ) of England in London, called
10608-585: The Stalhof or Steelyard . It remained until 1853, when the Hanseatic cities of Lübeck , Bremen and Hamburg sold the property to South Eastern Railway . Woollen cloth was shipped undyed and undressed from 14th/15th century London to the nearby shores of the Low Countries . Yet English maritime enterprise hardly reached beyond the seas of north-west Europe . The commercial route to Italy and
10764-495: The Thames , its primary geographical feature, a navigable river which crosses the city from the south-west to the east. The Thames Valley is a flood plain surrounded by gently rolling hills including Parliament Hill , Addington Hills , and Primrose Hill . Historically London grew up at the lowest bridging point on the Thames. The Thames was once a much broader, shallower river with extensive marshlands ; at high tide, its shores reached five times their present width. Since
10920-428: The Tower of London ; the site featuring the Palace of Westminster , Church of St. Margaret , and Westminster Abbey ; and the historic settlement in Greenwich where the Royal Observatory defines the prime meridian (0° longitude ) and Greenwich Mean Time . Other landmarks include Buckingham Palace , the London Eye , Piccadilly Circus , St Paul's Cathedral , Tower Bridge , and Trafalgar Square . The city has
11076-414: The Victorian era the Thames has been extensively embanked , and many of its London tributaries now flow underground . The Thames is a tidal river, and London is vulnerable to flooding. The threat has increased over time because of a slow but continuous rise in high water level caused by climate change and by the slow 'tilting' of the British Isles as a result of post-glacial rebound . London has
11232-559: 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
11388-436: 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
11544-536: 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
11700-402: 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
11856-516: The 11th century, London was clearly the largest town in England. Westminster Abbey , rebuilt in Romanesque style by King Edward the Confessor , was one of the grandest churches in Europe. Winchester had been the capital of Anglo-Saxon England , but from this time London became the main forum for foreign traders and the base for defence in time of war. In the view of Frank Stenton : "It had
12012-505: The 1814 defeat of Napoleon to reclaim the diamond, but his lawsuit ended prematurely with the return to power of Napoleon who had escaped from exile in Elba . Rundell had to flee Paris, returning again after the final defeat of Napoleon in June 1815 at the Battle of Waterloo . Rundell filed another lawsuit which was ultimately successful, allowing the return of the diamond to England. The diamond
12168-502: The 18th century, London was said to be dogged by crime, and the Bow Street Runners were established in 1750 as a professional police force. Epidemics during the 1720s and 30s saw most children born in the city die before reaching their fifth birthday. Coffee-houses became a popular place to debate ideas, as growing literacy and development of the printing press made news widely available, with Fleet Street becoming
12324-420: The City of London and the City of Westminster have city status . The City of London and the remainder of Greater London are both counties for the purposes of lieutenancies . The area of Greater London includes areas that are part of the historic counties of Middlesex , Kent , Surrey , Essex and Hertfordshire . More recently, Greater London has been defined as a region of England and in this context
12480-424: 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 a very high refractive index and
12636-455: The Khedive of Egypt". Apart from the sale date being too early, this is otherwise correct. It then went on to tell the tale of Ali Pasha, Ottoman pasha of Europe ordering destruction of the stone. This is apparently another case of confusion of similar names. This source also erroneously states the diamond weighted 85.8 carats (17.16 g), as do others, lending credence to the speculation that
12792-603: The London area. This called for the Corporation of the city to extend its jurisdiction and administration over expanding areas around the city. Fearing an attempt by the Crown to diminish the Liberties of London , coupled with a lack of interest in administering these additional areas or concern by city guilds of having to share power, caused the Corporation's "The Great Refusal", a decision which largely continues to account for
12948-513: The Ottomans in the earlier part of the conflict when the diamond was most likely sold. The fate of the diamond after this time has not been established. There are several stories about the diamond after it left England. One legend says that the diamond was sold to Ali Pasha of Tepelena , the Ottoman pasha of the western part of Rumelia , the empire's European territory. It then passed to
13104-565: The Pigot and Spoonmaker's diamond are the same. In 1858, an American magazine, Harper's New Monthly Magazine said that the diamond was brought to England in 1801, approximately 35 years later than the actual date, and was won in the lottery by a woman who then sold it to the Pasha of Egypt. This account bypasses the Christie's auction and the ownership by Rundell & Bridge. Dr. George Frederick Kunz , American mineralogist , wrote about
13260-564: The Pigot family could receive full value without a single buyer willing and able to pay such an amount. Such a plan required the approval of the Parliament , who was so petitioned in February 1800, because games of chance were normally illegal. The petition was considered in the House of Commons and the House of Lords . There were arguments made for and against allowing the lottery, and it
13416-623: The Rajah. It also may have been Muhammad Ali Khan Wallajah , the Nabob of Arcot . The diamond may have been mined at Golkonda . Diamonds were a common way to transfer money back to England at the time. Pigot brought it to London , probably in June 1764 when he returned to England aboard the East Indiaman Plassey after his first term as governor of Madras (1755–1763). The diamond was brought to England rough cut and subsequently cut as
13572-727: The Sultan Mahmud II , either in Ali Pasha's lifetime, as part of his complicated dealings with the central Ottoman government, or after his execution, when his possessions were confiscated by the Sultan. However, another version of this legend is that Ali Pasha held on to the diamond until his last day; when mortally wounded on 5 February 1822, the dying Ali Pasha reportedly ordered that it be crushed to powder in his presence – which it was. Since Ali Pasha died violently, having been shot multiple times and then immediately beheaded, this
13728-460: The Thames. Despite the evidence of scattered Brythonic settlements in the area, the first major settlement was founded by the Romans around 47 AD, about four years after their invasion of 43 AD. This only lasted until about 61 AD, when the Iceni tribe led by Queen Boudica stormed it and burnt it to the ground. The next planned incarnation of Londinium prospered, superseding Colchester as
13884-486: The United Kingdom's population and over 16% of England's population. The Greater London Built-up Area is the fourth-most populous in Europe, with about 9.8 million inhabitants as of 2011. The London metropolitan area is the third-most populous in Europe, with about 14 million inhabitants as of 2016, making London a megacity . Four World Heritage Sites are located in London: Kew Gardens ;
14040-620: The Viking incursions formally agreed by the Danish warlord , Guthrum and the West Saxon king Alfred the Great in 886. The Anglo-Saxon Chronicle records that Alfred "refounded" London in 886. Archaeological research shows this involved abandonment of Lundenwic and a revival of life and trade within the old Roman walls . London then grew slowly until a dramatic increase in about 950. By
14196-462: 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,
14352-420: 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
14508-410: 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
14664-512: 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 ,
14820-501: The centre of the British press. The invasion of Amsterdam by Napoleonic armies led many financiers to relocate to London and the first London international issue was arranged in 1817. Around the same time, the Royal Navy became the world's leading war fleet, acting as a major deterrent to potential economic adversaries. Following a fire in 1838, the Royal Exchange was redesigned by William Tite and rebuilt in 1844. The repeal of
14976-536: The city's metropolis. The City of London at its core once comprised the whole settlement, but as its urban area grew, the Corporation of London resisted attempts to amalgamate the city with its suburbs , causing "London" to be defined several ways. Forty per cent of Greater London is covered by the London post town , in which 'London' forms part of postal addresses. The London telephone area code (020) covers
15132-412: The city, to intimidate the inhabitants. In 1097, William II began building Westminster Hall , near the abbey. It became the basis of a new Palace of Westminster . In the 12th century, the institutions of central government, which had hitherto followed the royal English court around the country, grew in size and sophistication and became increasingly fixed, for most purposes at Westminster , although
15288-436: 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
15444-600: The combined revenue expenditure by London councils and the GLA amounted to just over £22 billion (£14.7 billion for the boroughs and £7.4 billion for the GLA). The London Fire Brigade is the statutory fire and rescue service for Greater London, run by the London Fire and Emergency Planning Authority . It is the third largest fire service in the world. National Health Service ambulance services are provided by
15600-501: 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
15756-626: The creation of the Greater London Authority . To mark the 21st century, the Millennium Dome , London Eye and Millennium Bridge were constructed. On 6 July 2005 London was awarded the 2012 Summer Olympics , as the first city to stage the Olympic Games three times. On 7 July 2005, three London Underground trains and a double-decker bus were bombed in a series of terrorist attacks . In 2008, Time named London alongside New York City and Hong Kong as Nylonkong , hailing them as
15912-559: The creation of the London Underground , the world's first urban rail network . The Metropolitan Board of Works oversaw infrastructure expansion in the capital and some surrounding counties; it was abolished in 1889 when the London County Council was created out of county areas surrounding the capital. From the early years of the 20th century onwards, teashops were found on High Streets across London and
16068-598: 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,
16224-522: The diamond as a gift for Mahmud II , the Ottoman sultan in Istanbul , one of many such gifts to Mahmud, possibly to compensate for Ali not supporting the Ottomans in the suppression of Greek during the Greek War of Independence of 1821–1832 (a position for which the sultan called for his execution) or to gain the sultan's acknowledgement of Ali's right to govern Egypt. An 1830 account details that
16380-413: The diamond but were unsuccessful as the perceived intrinsic value was so high and no reasonable offers were made. An alternate account is that Pigot left the diamond to his children. Although unmarried, he had several natural children at the time of his death, all of whom were minors. Regardless of this, the diamond remained in the extended Pigot family. A plan was conceived to conduct a lottery so that
16536-470: 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
16692-506: 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
16848-415: 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
17004-477: The diamond upon Napoleon's exile, to Ali Pasha of Tepelena, and upon his execution the diamond was confiscated by the Sultan Mahmud II and the "French Pigot Diamond" subsequently became the Spoonmaker's diamond. The existence of a different "French Pigot Diamond" is unlikely as only the English Pigot diamond is listed in diamond reference books. A contemporary reference, which states that it attempts to be
17160-592: The diamond was purchased in London by an agent of Muhammad Ali for Mahmud, and then taken by a British admiral in his coat pocket to the Royal Navy 's naval port in Portsmouth , from where he was to depart for the Mediterranean . Although England was one of the European nations that intervened on behalf of Greece and defeated the Ottoman fleet in the 1827 Battle of Navarino , it maintained cordial relations with
17316-407: 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
17472-713: The driest is 1921, with a total fall of 12.1 inches (308 mm). The average annual precipitation amounts to about 600mm, which is half the annual rainfall of New York City . Despite relatively low annual precipitation, London receives 109.6 rainy days on the 1.0mm threshold annually. London is vulnerable to climate change , and there is concern among hydrological experts that households may run out of water before 2050. Temperature extremes in London range from 40.2 °C (104.4 °F) at Heathrow on 19 July 2022 down to −17.4 °C (0.7 °F) at Northolt on 13 December 1981. Records for atmospheric pressure have been kept at London since 1692. The highest pressure ever reported
17628-449: 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
17784-609: The first Muslim mayor of a major Western capital. The mayor's statutory planning strategy is published as the London Plan , which was most recently revised in 2011. The local authorities are the councils of the 32 London boroughs and the City of London Corporation . They are responsible for most local services, such as local planning, schools, libraries, leisure and recreation, social services , local roads and refuse collection. Certain functions, such as waste management , are provided through joint arrangements. In 2009–2010
17940-408: 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
18096-455: 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
18252-644: The highest-ranked academic institutions in the world: Imperial College London in natural and applied sciences , the London School of Economics in social sciences , and the comprehensive University College London . It is the most visited city in Europe and has the world's busiest city airport system . The London Underground is the world's oldest rapid transit system. London's diverse cultures encompass over 300 languages. The 2023 population of Greater London of just under 10 million made it Europe's third-most populous city , accounting for 13.4% of
18408-423: 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
18564-474: 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
18720-640: The location of its original headquarters in a road called Great Scotland Yard in Whitehall. The City of London has its own police force – the City of London Police . First worn by Met police officers in 1863, the custodian helmet has been called a "cultural icon" and a "symbol of British law enforcement". Introduced by the Met in 1929, the blue police telephone box (basis for the TARDIS in Doctor Who )
18876-475: The lottery beginning in August. Tickets were available from stockbrokers, jewellers, newspapers, and other companies. The winning number, 9,488 was drawn on 2 March 1801 in Guildhall, London and had been purchased jointly by John Cruikshank, Richard Blanchford, and John Henderson of London and William Thompson of Walworth . The ticket was sold by Hornsby & Co. The next known sale occurred in 1802 when it
19032-467: 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
19188-409: The mayor's budget proposals each year. The GLA has responsibility for the majority of London's transport system through its functional arm Transport for London (TfL), it is responsible for overseeing the city's police and fire services, and also for setting a strategic vision for London on a range of issues. The headquarters of the GLA is City Hall , Newham. The mayor since 2016 has been Sadiq Khan ,
19344-591: 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
19500-579: 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
19656-753: The most museums , art galleries, libraries, and cultural venues in the UK, including the British Museum , National Gallery , Natural History Museum , Tate Modern , British Library , and numerous West End theatres. Important sporting events held in London include the FA Cup Final , the Wimbledon Tennis Championships , and the London Marathon . It became the first city to host three Summer Olympic Games upon hosting
19812-675: The most diverse cities in the world. In 1951, the Festival of Britain was held on the South Bank . The Great Smog of 1952 led to the Clean Air Act 1956 , which ended the " pea soup fogs " for which London had been notorious, and had earned it the nickname the "Big Smoke". Starting mainly in the mid-1960s, London became a centre for worldwide youth culture , exemplified by the Swinging London sub-culture associated with
19968-481: The mysterious Pigot Diamond in 1897 for the Century Magazine . 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 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
20124-469: 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
20280-455: The offer, probably because he was aware it came from England, with whom he was still at war. The Times of London prematurely reported on 26 November 1804 that Napoleon had purchased the diamond. Due to the conflict, the diamond was not immediately returned to England. It remained in France until 1816 when the situation stabilised and several lawsuits over the diamond were concluded. Parker
20436-467: The old Roman city. By about 680 the city had become a major port again, but there is little evidence of large-scale production. From the 820s repeated Viking assaults brought decline. Three are recorded; those in 851 and 886 succeeded, while the last, in 994, was rebuffed. The Vikings applied Danelaw over much of eastern and northern England, its boundary running roughly from London to Chester as an area of political and geographical control imposed by
20592-584: The origin of the Spoonmaker's diamond and how it came to the Ottoman Empire is not known. One version of the Spoonmaker's history is that a French officer named Pigot purchased the diamond from the Maharajah of Madras in 1774 (less than 10 years after Sir George Pigot received the Pigot diamond) and brought it to France from India. The diamond passed through several owners and was then sold by auction to Madam Bonaparte , Napoleon's mother. She then sold
20748-620: 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
20904-490: The principal city of the Roman province of Britannia in 100. At its height in the 2nd century, Roman London had a population of about 60,000. With the early 5th-century collapse of Roman rule, the walled city of Londinium was effectively abandoned, although Roman civilisation continued around St Martin-in-the-Fields until about 450. From about 500, an Anglo-Saxon settlement known as Lundenwic developed slightly west of
21060-465: The resources, and it was rapidly developing the dignity and the political self-consciousness appropriate to a national capital ." After winning the Battle of Hastings , William, Duke of Normandy was crowned King of England in newly completed Westminster Abbey on Christmas Day 1066. William built the Tower of London , the first of many such in England rebuilt in stone in the south-eastern corner of
21216-641: The rest of Britain, with Lyons , who opened the first of their chain of teashops in Piccadilly in 1894, leading the way. The tearooms, such as the Criterion in Piccadilly, became a popular meeting place for women from the suffrage movement. The city was the target of many attacks during the suffragette bombing and arson campaign , between 1912 and 1914, which saw historic landmarks such as Westminster Abbey and St Paul's Cathedral bombed. London
21372-401: The royal treasury came to rest in the Tower . While the City of Westminster developed into a true governmental capital, its distinct neighbour, the City of London , remained England's largest city and principal commercial centre and flourished under its own unique administration, the Corporation of London . In 1100, its population was some 18,000; by 1300 it had grown to nearly 100,000. With
21528-546: The sea. London is the seat of the Government of the United Kingdom . Many government departments, as well as the prime minister's residence at 10 Downing Street , are based close to the Palace of Westminster , particularly along Whitehall . There are 75 members of Parliament (MPs) from London; As of June 2024 , 59 are from the Labour Party , 9 are Conservatives , 6 are Liberal Democrats and one constituency
21684-529: 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
21840-419: 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,
21996-424: The start of 2018 to mid April 2018. Funding cuts to police in London are likely to have contributed to this, though other factors are involved. However, homicide figures fell in 2022 with 109 recorded for the year, and the murder rate in London is much lower than other major cities around the world. London, also known as Greater London , is one of nine regions of England and the top subdivision covering most of
22152-524: 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
22308-753: The theatres in the 1640s. The ban on theatre was lifted during the Restoration in 1660, and London's oldest operating theatre, Drury Lane , opened in 1663 in what is now the West End theatre district. By the end of the Tudor period in 1603, London was still compact. There was an assassination attempt on James I in Westminster, in the Gunpowder Plot of 5 November 1605. In 1637, the government of Charles I attempted to reform administration in
22464-442: The time . Since the 19th century, the name "London" has referred to the metropolis around the City of London, historically split between the counties of Middlesex , Essex , Surrey , Kent , and Hertfordshire , which since 1965 has largely comprised the administrative area of Greater London , governed by 33 local authorities and the Greater London Authority . As one of the world's major global cities , London exerts
22620-715: The unique governmental status of the City . In the English Civil War , the majority of Londoners supported the Parliamentary cause. After an initial advance by the Royalists in 1642, culminating in the battles of Brentford and Turnham Green , London was surrounded by a defensive perimeter wall known as the Lines of Communication . The lines were built by up to 20,000 people, and were completed in under two months. The fortifications failed their only test when
22776-454: 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
22932-430: 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
23088-639: The world's three most influential global cities . In January 2015, Greater London's population was estimated to be 8.63 million, its highest since 1939. During the Brexit referendum in 2016, the UK as a whole decided to leave the European Union , but most London constituencies voted for remaining. However, Britain's exit from the EU in early 2020 only marginally weakened London's position as an international financial centre. The administration of London
23244-1023: Was bombed by the Germans in the First World War , and during the Second World War , the Blitz and other bombings by the German Luftwaffe killed over 30,000 Londoners, destroying large tracts of housing and other buildings across the city. The tomb of the Unknown Warrior , an unidentified member of the British armed forces killed during the First World War, was buried in Westminster Abbey on 11 November 1920. The Cenotaph , located in Whitehall ,
23400-415: Was anxious to obtain his share of the stone and contemplated a lawsuit which might have resulted in the diamond being divided into pieces, thus greatly reducing its value. Instead, Rundell and Bridge bought out Parker's share and became sole owners. An alternate report is that Parker filed a lawsuit to determine the value of his share of the diamond, resulting in the buyout. E. W. Rundell went to France after
23556-444: Was approved on 2 July 1800. The act was titled An Act to enable Sir George Pigot Baronet, Margaret Fischer and Frances Pigot, to dispose of a certain Diamond by a Lottery or the Pigot and Fisher Diamond Lottery Act 1800. The terms of the lottery were that 11,428 tickets could be sold for two guineas each. Therefore, the sale of all tickets would realize £23,998. The value had been estimated at £25,000 to £30,000. Newspapers advertised
23712-447: Was known to be in London in 1818 and 1821. Rundell and Bridge continued trying to sell the diamond, sending models to all the crowned heads of Europe . Rundell and Bridge finally sold the diamond to Muhammad Ali of Egypt , the self-declared Khedive of Egypt, for £30,000, the sale having been negotiated by Samuel Briggs, the British Consul in Alexandria . The date of this sale is given as 1822, 1823, and 1830. Mohammed Ali purchased
23868-437: Was once a common sight throughout London and regional cities in the UK. The British Transport Police are responsible for police services on National Rail , London Underground , Docklands Light Railway and Tramlink services. The Ministry of Defence Police is a special police force in London, which does not generally become involved with policing the general public. The UK's domestic counter-intelligence service ( MI5 )
24024-462: Was sold by auction, as weighing 188 grains (47 carats) at Christie's on Pall Mall , the centre of London's fine art scene at the time, on 10 May for £9,500 to a pawnbroker in Soho , a Mr. Parker of Parker and Birketts. Parker may have been acting on behalf of the famous London jewellers, Rundell and Bridge who in 1804 had obtained part ownership. Christie's used this description of the diamond: Its owners were unfortunate in its being brought to
24180-406: Was supervised by polymath Robert Hooke . In 1710, Christopher Wren 's masterpiece, St Paul's Cathedral , was completed, replacing its medieval predecessor that burned in the Great Fire of 1666. The dome of St Paul's dominated the London skyline for centuries, inspiring the artworks and writing of William Blake , with his 1789 poem " Holy Thursday " referring to 'the high dome of Pauls'. During
24336-458: Was unveiled on the same day, and is the focal point for the National Service of Remembrance held annually on Remembrance Sunday , the closest Sunday to 11 November. The 1948 Summer Olympics were held at the original Wembley Stadium , while London was still recovering from the war. From the 1940s, London became home to many immigrants, primarily from Commonwealth countries such as Jamaica, India, Bangladesh and Pakistan, making London one of
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