It extends from the nominal red edge of the visible spectrum at 700 nanometers, to 1000000 nm. Most of the radiation emitted by objects near room temperature is infrared. Like all EMR, IR carries radiant energy, and behaves both like a wave and like its quantum particle, the photon, slightly more than half of the total energy from the Sun was eventually found to arrive on Earth in the form of infrared. The balance between absorbed and emitted infrared radiation has an effect on Earths climate. Infrared radiation is emitted or absorbed by molecules when they change their rotational-vibrational movements and it excites vibrational modes in a molecule through a change in the dipole moment, making it a useful frequency range for study of these energy states for molecules of the proper symmetry. Infrared spectroscopy examines absorption and transmission of photons in the infrared range, Infrared radiation is used in industrial and medical applications. Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected, Infrared thermal-imaging cameras are used to detect heat loss in insulated systems, to observe changing blood flow in the skin, and to detect overheating of electrical apparatuses.
Thermal-infrared imaging is used extensively for military and civilian purposes, military applications include target acquisition, night vision and tracking. Humans at normal body temperature radiate chiefly at wavelengths around 10 μm, Infrared radiation extends from the nominal red edge of the visible spectrum at 700 nanometers to 1 mm. This range of wavelengths corresponds to a range of approximately 430 THz down to 300 GHz. Below infrared is the portion of the electromagnetic spectrum. Sunlight, at a temperature of 5,780 kelvins, is composed of near thermal-spectrum radiation that is slightly more than half infrared. At zenith, sunlight provides an irradiance of just over 1 kilowatt per square meter at sea level, of this energy,527 watts is infrared radiation,445 watts is visible light, and 32 watts is ultraviolet radiation. Nearly all the radiation in sunlight is near infrared, shorter than 4 micrometers. On the surface of Earth, at far lower temperatures than the surface of the Sun, almost all thermal radiation consists of infrared in mid-infrared region, much longer than in sunlight.
Of these natural thermal radiation processes only lightning and natural fires are hot enough to produce much visible energy, thermal infrared radiation has a maximum emission wavelength, which is inversely proportional to the absolute temperature of object, in accordance with Wiens displacement law. Therefore, the band is often subdivided into smaller sections. Due to the nature of the blackbody radiation curves, typical hot objects, such as exhaust pipes, the three regions are used for observation of different temperature ranges, and hence different environments in space
Crystallographic defects in diamond
Imperfections in the crystal lattice of diamond are common. Such crystallographic defects in diamond may be the result of irregularities or extrinsic substitutional or interstitial impurities. Absorption spectrum is used not only to identify the defects, but to estimate their concentration, there is a tradition in diamond spectroscopy to label a defect-induced spectrum by a numbered acronym. This tradition has been followed in general with some notable deviations, many acronyms are confusing though, Some symbols are too similar. Accidentally, same labels were given to different centers detected by EPR, whereas some acronyms are logical, such as N3 or H3, many are not. In particular, there is no distinction between the meaning of labels GR, R and TR. The symmetry of defects in crystals is described by the point groups and they differ from the space groups describing the symmetry of crystals by absence of translations, and thus are much fewer in number. In diamond, only defects of the following symmetries have been observed thus far, tetragonal, the defect symmetry allows predicting many optical properties.
For example, one-phonon absorption in pure diamond lattice is forbidden because the lattice has an inversion center, introducing any defect breaks the crystal symmetry resulting in defect-induced infrared absorption, which is the most common tool to measure the defect concentrations in diamond. In synthetic diamond grown by the high-pressure high-temperature synthesis or chemical vapor deposition, such alignment has been been observed in gallium arsenide and thus is not unique to diamond. Various elemental analyses of diamond reveal a range of impurities. They mostly originate, from inclusions of foreign materials in diamond, virtually any element can be hammered into diamond by ion implantation. More essential are elements which can be introduced into the lattice as isolated atoms during the diamond growth. By 2008, those elements are nitrogen, hydrogen, phosphorus, cobalt and tungsten have been unambiguously detected in diamond, but they might originate from foreign inclusions. Detection of isolated iron in diamond has been re-interpreted in terms of micro-particles of ruby produced during the diamond synthesis, oxygen is believed to be a major impurity in diamond, but it has not been spectroscopically identified in diamond yet.
Two electron paramagnetic resonance centers have been assigned to nitrogen–oxygen complexes, the assignment is indirect and the corresponding concentrations are rather low. The most common impurity in diamond is nitrogen, which can comprise up to 1% of a diamond by mass. Previously, all defects in diamond were thought to be the result of structural anomalies, research revealed nitrogen to be present in most diamonds
The Cullinan Diamond is the largest gem-quality rough diamond ever found, weighing 3,106.75 carats, discovered at the Premier No.2 mine in Cullinan, modern-day South Africa, on 26 January 1905. It was named after the chairman of the mine, Thomas Cullinan and it was the largest polished diamond of any colour until the discovery in 1985 of the Golden Jubilee Diamond, from the Premier Mine. Cullinan I is mounted in the head of the Sovereigns Sceptre with Cross, the second-largest is Cullinan II or the Second Star of Africa, at 317.4 carats it is the fourth-largest cut diamond in the world, and is mounted in the Imperial State Crown. Both diamonds are part of the Crown Jewels which belong to the monarch in right of the Crown, at approximately 1 1⁄3 pounds,3 7⁄8 inches long,2 1⁄4 inches wide and 2 5⁄8 inches high the diamond was twice the size of any previously discovered. Wells immediately took it for examination, Sir William Crookes performed an analysis of the Cullinan diamond, ascertaining a weight of 3,106 carats.
The stone was named after Sir Thomas Cullinan, the owner of the diamond mine. Crookes mentioned its remarkable clarity, but a spot in the middle. The colours around the spot were very vivid and changed as the analyser was turned. According to Crookes, this pointed to internal strain, such strain is not uncommon in diamonds. Because one side of the diamond was perfectly smooth, it was concluded that the stone had originally been part of a larger diamond. Crookes pronounced the Cullinan a fragment, probably less than half, of an octahedral crystal. The discovery became a sensation, with the developments being followed avidly by the press. Wells was awarded £3,500 for the find and the diamond was purchased by the Transvaal Colony government for £150,000 and insured for ten times the amount. Prime Minister Louis Botha suggested that the diamond be presented to King Edward VII as a token of the loyalty and attachment of the people of Transvaal to his throne, a vote was staged in order for the government to find out what should be done with the diamond.
In the aftermath of the Boer Wars the Boers voted in favour of presenting the king with the diamond, the final vote was 42 against and 19 in favour. In the wake of the vote, the British prime minister of the time, Henry Campbell-Bannerman, future prime minister Winston Churchill eventually managed to persuade the king to accept, to which Edward VII finally agreed. Churchill was presented with a replica of the diamond, which he delighted in showing off to friends. In 1905, due to the value of the Cullinan
Argyle diamond mine
The Argyle Diamond Mine is a diamond mine located in the East Kimberley region in the remote north of Western Australia. Argyle is the largest diamond producer in the world by volume and it is the only known significant source of pink and red diamonds, producing over 90% of the worlds supply. It additionally provides a large proportion of other naturally coloured diamonds, including champagne, cognac, on June 21,2015, after more than 11 years and 42 kilometres of tunnelling, the Argyle underground block cave development was officially completed. In 2013, Argyle is estimated to produce 10.2 million carats with an average per carat price of $25/carat. The Argyle mine is owned by the Rio Tinto Group, a mining company which owns the Diavik Diamond Mine in Canada. The mine site covers about 50 ha, stretching in a linear shape about 1600 m long and 150 to 600 m wide. The mine is of open pit construction, and reaches about 600 m deep at its deepest point, the open cut closed in 2010. An underground block cave mine is currently under development, and is likely to extend Argyles diamond production until 2018, the Argyle diamond mine is located in the Kimberley region in the far northeast of the Australian state of Western Australia.
It is located to the southwest of Lake Argyle in the Matsu Ranges, because it is 185 km by road from the nearest settlement, a complete residential camp has been constructed on site. Most of the 520 workers commute from Perth, over 2,000 km away, the mine has encouraged local employment and has a large number of indigenous local people working within the mine. The mine is the first successful commercial diamond mine not located on a kimberlite pipe, the pipe is named AK-1, although it is commonly simply called the Argyle pipe. The volcanic pipe is a diatreme, composed of olivine lamproite, present as tuff, peripheral volcanic facies suggest the lamproite eruption formed a maar. At the margins of the pipe the lamproite is mixed with a volcanic breccia containing shattered wall rock fragments mixed and milled by the eruption. Minerals in the marginal facies include zeolite minerals, micas and clays, diamonds are found within the intact core of the volcanic pipe, as well as within some of the marginal breccia facies and maar facies.
However, some diamonds are considered to have been resorbed during the cooling of the pipe. The diatreme pipe formed by explosive eruption of the magma through a zone of weakness in the continental crust. The diamonds found at the Argyle pipe have been dated to about 1.58 billion years of age and this represents a relatively short period during which diamond formation could have taken place, which may explain the small average size and unusual physical characteristics of Argyle diamonds. Diamonds found in the Argyle pipe are predominantly eclogitic, meaning that the carbon is of organic origin, in addition to the pipe itself, a number of semipermanent streams have eroded away portions of the pipe and created significant alluvial deposits of diamonds
Nitrogen is a chemical element with symbol N and atomic number 7. It was first discovered and isolated by Scottish physician Daniel Rutherford in 1772, although Carl Wilhelm Scheele and Henry Cavendish had independently done so at about the same time, Rutherford is generally accorded the credit because his work was published first. Nitrogen is the lightest member of group 15 of the periodic table, the name comes from the Greek πνίγειν to choke, directly referencing nitrogens asphyxiating properties. It is an element in the universe, estimated at about seventh in total abundance in the Milky Way. At standard temperature and pressure, two atoms of the element bind to form dinitrogen, a colourless and odorless diatomic gas with the formula N2, dinitrogen forms about 78% of Earths atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids, in the nucleic acids, the human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen and hydrogen.
The nitrogen cycle describes movement of the element from the air, into the biosphere and organic compounds, many industrially important compounds, such as ammonia, nitric acid, organic nitrates, and cyanides, contain nitrogen. The extremely strong bond in elemental nitrogen, the second strongest bond in any diatomic molecule. Synthetically produced ammonia and nitrates are key industrial fertilisers, and fertiliser nitrates are key pollutants in the eutrophication of water systems. Apart from its use in fertilisers and energy-stores, nitrogen is a constituent of organic compounds as diverse as Kevlar used in high-strength fabric, Nitrogen is a constituent of every major pharmacological drug class, including antibiotics. Many notable nitrogen-containing drugs, such as the caffeine and morphine or the synthetic amphetamines. Nitrogen compounds have a long history, ammonium chloride having been known to Herodotus. They were well known by the Middle Ages, alchemists knew nitric acid as aqua fortis, as well as other nitrogen compounds such as ammonium salts and nitrate salts.
The mixture of nitric and hydrochloric acids was known as aqua regia, celebrated for its ability to dissolve gold, the discovery of nitrogen is attributed to the Scottish physician Daniel Rutherford in 1772, who called it noxious air. Though he did not recognise it as a different chemical substance, he clearly distinguished it from Joseph Blacks fixed air. The fact that there was a component of air that does not support combustion was clear to Rutherford, Nitrogen was studied at about the same time by Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley, who referred to it as burnt air or phlogisticated air. Nitrogen gas was inert enough that Antoine Lavoisier referred to it as air or azote, from the Greek word άζωτικός. In an atmosphere of nitrogen, animals died and flames were extinguished
Absorption spectroscopy refers to spectroscopic techniques that measure the absorption of radiation, as a function of frequency or wavelength, due to its interaction with a sample. The sample absorbs energy, i. e. photons, from the radiating field, the intensity of the absorption varies as a function of frequency, and this variation is the absorption spectrum. Absorption spectroscopy is performed across the electromagnetic spectrum and ultraviolet-visible spectroscopy are particularly common in analytical applications. Absorption spectroscopy is employed in studies of molecular and atomic physics, astronomical spectroscopy. There are a range of experimental approaches for measuring absorption spectra. The most common arrangement is to direct a beam of radiation at a sample. The transmitted energy can be used to calculate the absorption, the source, sample arrangement and detection technique vary significantly depending on the frequency range and the purpose of the experiment. A materials absorption spectrum is the fraction of incident radiation absorbed by the material over a range of frequencies, the absorption spectrum is primarily determined by the atomic and molecular composition of the material.
Radiation is more likely to be absorbed at frequencies that match the difference between two quantum mechanical states of the molecules. The absorption that occurs due to a transition between two states is referred to as a line and a spectrum is typically composed of many lines. The frequencies where absorption lines occur, as well as their relative intensities, primarily depend on the electronic, the frequencies will depend on the interactions between molecules in the sample, the crystal structure in solids, and on several environmental factors. The lines will have a width and shape that are determined by the spectral density or the density of states of the system. Absorption lines are classified by the nature of the quantum mechanical change induced in the molecule or atom. Rotational lines, for instance, occur when the state of a molecule is changed. Rotational lines are found in the microwave spectral region. Vibrational lines correspond to changes in the state of the molecule and are typically found in the infrared region.
Electronic lines correspond to a change in the state of an atom or molecule and are typically found in the visible. X-ray absorptions are associated with the excitation of inner shell electrons in atoms and these changes can be combined, leading to new absorption lines at the combined energy of the two changes
Diamond enhancements are specific treatments, performed on natural diamonds, which are designed to improve the visual gemological characteristics of the diamond in one or more ways. The CIBJO and government agencies such as the United States Federal Trade Commission explicitly require the disclosure of all diamond treatments at the time of sale and color enhanced diamonds sell at lower price points when compared to similar, untreated diamonds. This is because enhanced diamonds are originally lower quality before the enhancement is performed, after enhancement, the diamonds may visually appear as good as their non-enhanced counterparts. Therefore, treated diamonds appear to have a greater value than they would before treatment, the clarity, or purity, of a diamond refers to internal inclusions of the diamond, and is one of the 4-Cs in determining a diamonds value. Diamonds may have other inclusions such as air bubbles and mineral deposits such as iron or garnet, the size and position of the inclusions are factors in determining the value of a diamond, especially when the other gemological characteristics are of a higher standard.
The development of drilling techniques have increased the ability to selectively target, remove. The laser drilling process involves the use of a laser to bore very fine holes into a diamond to create a route of access to a black carbon crystal inclusion. The laser burns a narrow tube or channel to the inclusion, once the location of included black carbon crystal has been reached by the drill channel, the diamond is soaked in sulfuric acid to dissolve the black carbon crystal. After soaking in sulfuric acid the black carbon crystal will dissolve and become transparent, under microscopic inspection the fine drill or bore holes can be seen, but are not distracting and do not affect sparkle or brilliance of the diamond. The channels are microscopic so that dirt or debris cannot travel down the channel and this technology became available roughly 20 years after the time the laser drilling technique was developed. Simply put, fracture filling makes tiny natural fractures inside diamonds less visible to the eye or even under magnification.
Fractures are very common inside diamonds and are created during the creation in the earths crust. As the rough diamond travels up from the earths crust through volcanic pipes it comes under extreme stresses and pressures and this process, which involves the use of specially-formulated solutions with a refractive index approximating that of diamond, was pioneered by Zvi Yehuda of Ramat Gan, Israel. Yehuda is now used as a name applied to diamonds treated in this manner. Koss & Schechter, another Israel-based firm, attempted to modify Yehudas process in the 1990s by using halogen-based glasses, the details behind the Yehuda process have been kept secret, but the filler used is reported to be lead oxychloride glass, which has a fairly low melting point. The flashes are best seen with the field of nearly parallel to the filled fractures plane. In strongly colored diamonds the flash effect may be missed if examination is less than thorough, for example, in brown-tinted champagne diamonds, the orange-yellow flashes are concealed, leaving only the blue-purple flashes to be seen.
For this reason fracture-filling is normally applied to stones whose size is large enough to justify the treatment, however
The Koh-i-Noor is a large, colourless diamond that was found near Guntur in Andhra Pradesh, possibly in the 13th century. According to legend, it first weighed 793 carats uncut, although the earliest well-attested weight is 186 carats, in 1852, Prince Albert, the husband of Queen Victoria, unhappy with its dull and irregular appearance, ordered it cut down from 186 carats. It emerged 42 percent lighter as a dazzling oval-cut brilliant weighing 105.6 carats, as the diamonds history involves a great deal of fighting between men, the Koh-i-Noor acquired a reputation within the British royal family for bringing bad luck to any man who wears it. Since arriving in the country, it has ever been worn by female members of the family. Today, the diamond is set in the front of the Queen Mothers Crown, part of the Crown Jewels of the United Kingdom, and is seen by millions of visitors to the Tower of London each year. The governments of India, Pakistan and Afghanistan have all tried to claim ownership of the Koh-i-Noor and demanded its return at various points in recent decades.
However, the early history is lost in the mists of time. It is however impossible to know where it was found, in the early 14th century, Alauddin Khalji, second ruler of the Turkic Khalji dynasty of the Delhi Sultanate, and his army began looting the kingdoms of southern India. Malik Kafur, Khiljis general, made a raid on Warangal in 1310. He called the stone the Diamond of Babur at the time, both Babur and his son and successor, mentioned the origins of this diamond in their memoirs, thought by many historians to be the earliest reliable reference to the Koh-i-Noor. Shah Jahan, the fifth Mughal emperor, had the stone placed into his ornate Peacock Throne, in 1658, his son and successor, confined the ailing emperor at nearby Agra Fort. While in the possession of Aurangazeb, it was cut by Hortenso Borgia. For this carelessness, Borgia was reprimanded and fined 10,000 rupees, according to recent research the story of Borgia cutting the diamond is not correct, and most probably mixed up with the Orlov, part of Catherine the Greats imperial Russian sceptre in the Kremlin.
Along with a host of items, including the Daria-i-Noor, as well as the Peacock Throne. When he finally managed to obtain the stone, and that is how the stone got its name. It is estimated that the worth of the treasures plundered came to 700 million rupees. This was roughly equivalent to £87.5 million sterling at the time, the riches gained by the Afsharid Empire from the Indian campaign were so monumental that Nader Shah made a proclamation alleviating all subjects of the Empire from taxes for a total of three years. After the assassination of Nader Shah in 1747 and the collapse of his empire, the stone came into the hands of one of his generals, Ahmad Shah Durrani, who became the Emir of Afghanistan
Diamond is a metastable allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the rate from diamond to graphite is negligible at standard conditions. Diamond is renowned as a material with superlative physical qualities, most of which originate from the covalent bonding between its atoms. In particular, diamond has the highest hardness and thermal conductivity of any bulk material and those properties determine the major industrial application of diamond in cutting and polishing tools and the scientific applications in diamond knives and diamond anvil cells. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron, small amounts of defects or impurities color diamond blue, brown, purple, orange or red. Diamond has relatively high optical dispersion, most natural diamonds are formed at high temperature and pressure at depths of 140 to 190 kilometers in the Earths mantle.
Carbon-containing minerals provide the source, and the growth occurs over periods from 1 billion to 3.3 billion years. Diamonds are brought close to the Earths surface through deep volcanic eruptions by magma, Diamonds can be produced synthetically in a HPHT method which approximately simulates the conditions in the Earths mantle. An alternative, and completely different growth technique is chemical vapor deposition, several non-diamond materials, which include cubic zirconia and silicon carbide and are often called diamond simulants, resemble diamond in appearance and many properties. Special gemological techniques have developed to distinguish natural diamonds, synthetic diamonds. The word is from the ancient Greek ἀδάμας – adámas unbreakable, the name diamond is derived from the ancient Greek αδάμας, unalterable, untamed, from ἀ-, un- + δαμάω, I overpower, I tame. Diamonds have been known in India for at least 3,000 years, Diamonds have been treasured as gemstones since their use as religious icons in ancient India.
Their usage in engraving tools dates to early human history, in 1797, the English chemist Smithson Tennant repeated and expanded that experiment. By demonstrating that burning diamond and graphite releases the same amount of gas, the most familiar uses of diamonds today are as gemstones used for adornment, a use which dates back into antiquity, and as industrial abrasives for cutting hard materials. The dispersion of light into spectral colors is the primary gemological characteristic of gem diamonds. In the 20th century, experts in gemology developed methods of grading diamonds, four characteristics, known informally as the four Cs, are now commonly used as the basic descriptors of diamonds, these are carat, cut and clarity. A large, flawless diamond is known as a paragon and these conditions are met in two places on Earth, in the lithospheric mantle below relatively stable continental plates, and at the site of a meteorite strike. The conditions for diamond formation to happen in the mantle occur at considerable depth corresponding to the requirements of temperature and pressure
Infrared spectroscopy involves the interaction of infrared radiation with matter. It covers a range of techniques, mostly based on absorption spectroscopy, as with all spectroscopic techniques, it can be used to identify and study chemicals. Sample may be solid, liquid, or gas, the method or technique of infrared spectroscopy is conducted with an instrument called an infrared spectrometer to produce an infrared spectrum. An IR spectrum is essentially a graph of infrared light absorbance on the vertical axis vs. frequency or wavelength on the horizontal axis, typical units of frequency used in IR spectra are reciprocal centimeters, with the symbol cm−1. Units of IR wavelength are commonly given in micrometers, symbol μm, a common laboratory instrument that uses this technique is a Fourier transform infrared spectrometer. Two-dimensional IR is possible as discussed below, the infrared portion of the electromagnetic spectrum is usually divided into three regions, the near-, mid- and far- infrared, named for their relation to the visible spectrum.
The higher-energy near-IR, approximately 14000–4000 cm−1 can excite overtone or harmonic vibrations, the mid-infrared, approximately 4000–400 cm−1 may be used to study the fundamental vibrations and associated rotational-vibrational structure. The far-infrared, approximately 400–10 cm−1, lying adjacent to the region, has low energy. The names and classifications of these subregions are conventions, and are loosely based on the relative molecular or electromagnetic properties. Infrared spectroscopy exploits the fact that molecules absorb frequencies that are characteristic of their structure and these absorptions occur at resonant frequencies, i. e. the frequency of the absorbed radiation matches the vibrational frequency. The energies are affected by the shape of the potential energy surfaces, the masses of the atoms. In particular, in the Born–Oppenheimer and harmonic approximations, i. e, the resonant frequencies are related to the strength of the bond and the mass of the atoms at either end of it.
Thus, the frequency of the vibrations are associated with a normal mode of motion. In order for a mode in a sample to be IR active. A permanent dipole is not necessary, as the rule requires only a change in dipole moment, a molecule can vibrate in many ways, and each way is called a vibrational mode. For molecules with N number of atoms, linear molecules have 3N –5 degrees of vibrational modes, as an example H2O, a non-linear molecule, will have 3 ×3 –6 =3 degrees of vibrational freedom, or modes. Simple diatomic molecules have only one bond and only one vibrational band, if the molecule is symmetrical, e. g. N2, the band is not observed in the IR spectrum, but only in the Raman spectrum. Asymmetrical diatomic molecules, e. g. CO, absorb in the IR spectrum, more complex molecules have many bonds, and their vibrational spectra are correspondingly more complex, i. e. big molecules have many peaks in their IR spectra
South Africa, officially the Republic of South Africa, is the southernmost country in Africa. South Africa is the 25th-largest country in the world by land area and it is the southernmost country on the mainland of the Old World or the Eastern Hemisphere. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different Bantu languages, the remaining population consists of Africas largest communities of European and multiracial ancestry. South Africa is a multiethnic society encompassing a variety of cultures, languages. Its pluralistic makeup is reflected in the recognition of 11 official languages. The country is one of the few in Africa never to have had a coup détat, the vast majority of black South Africans were not enfranchised until 1994. During the 20th century, the black majority sought to recover its rights from the dominant white minority, with this struggle playing a role in the countrys recent history. The National Party imposed apartheid in 1948, institutionalising previous racial segregation, since 1994, all ethnic and linguistic groups have held political representation in the countrys democracy, which comprises a parliamentary republic and nine provinces.
South Africa is often referred to as the Rainbow Nation to describe the multicultural diversity. The World Bank classifies South Africa as an economy. Its economy is the second-largest in Africa, and the 34th-largest in the world, in terms of purchasing power parity, South Africa has the seventh-highest per capita income in Africa. However and inequality remain widespread, with about a quarter of the population unemployed, South Africa has been identified as a middle power in international affairs, and maintains significant regional influence. The name South Africa is derived from the geographic location at the southern tip of Africa. Upon formation the country was named the Union of South Africa in English, since 1961 the long form name in English has been the Republic of South Africa. In Dutch the country was named Republiek van Zuid-Afrika, replaced in 1983 by the Afrikaans Republiek van Suid-Afrika, since 1994 the Republic has had an official name in each of its 11 official languages. Mzansi, derived from the Xhosa noun umzantsi meaning south, is a name for South Africa.
South Africa contains some of the oldest archaeological and human fossil sites in the world, extensive fossil remains have been recovered from a series of caves in Gauteng Province. The area is a UNESCO World Heritage site and has termed the Cradle of Humankind