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Encyclopedia > Diamond
Diamond

A scattering of round-brilliant cut diamonds shows off the many reflecting facets.
General
Category Native Minerals
Chemical formula C
Identification
Molecular Weight 12.01 u
Color Typically yellow, brown or gray to colorless. Less often in blue, green, black, translucent white, pink, violet, orange, purple and red.[1]
Crystal habit Octahedral
Crystal system Isometric-Hexoctahedral (Cubic)
Cleavage 111 (perfect in four directions)
Fracture Conchoidal - step like
Mohs Scale hardness 10[1]
Luster Adamantine[1]
Polish luster Adamantine[1]
Refractive index 2.4175–2.4178
Optical Properties Singly Refractive[1]
Birefringence none[1]
Dispersion .044[1]
Pleochroism none[1]
Ultraviolet fluorescence colorless to yellowish stones - inert to strong in long wave, and typically blue. Weaker in short wave.[1]
Absorption spectra In pale yellow stones a 415.5 nm line is typical. Irradiated and annealed diamonds often show a line around 594 nm when cooled to low temperatures.[1]
Streak White
Specific gravity 3.52 (+/- .01)[1]
Density 3.5-3.53
Diaphaneity Transparent to subtransparent to translucent

Diamond is an allotrope of carbon. It is the hardest known natural material and the third-hardest known material after aggregated diamond nanorods and ultrahard fullerite. Its hardness and high dispersion of light make it useful for industrial applications and jewelry. As a gemstone, diamond is perhaps the most valued. ... In mathematics, and particularly in axiomatic set theory, â—ŠS (diamondsuit or diamond) is a certain family of combinatorial principles. ... Look up diamond in Wiktionary, the free dictionary. ... Description: Diamonds Info: Photographed by Mario Sarto on February 4, 2004 License: GNU Free Documentation License File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A chemical formula is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... The molecular mass of a substance (less accurately called molecular weight and abbreviated as MW) is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... In mineralogy, shape and size give rise to descriptive terms applied to the typical appearance, or habit of crystals. ... An octahedron (plural: octahedra) is a polyhedron with eight faces. ... A crystal system is a category of space groups, which characterize symmetry of structures in three dimensions with translational symmetry in three directions, having a discrete class of point groups. ... Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite planes, creating smooth surfaces, of which there are several named types: Basal cleavage: cleavage parallel to the base of a crystal, or to the plane of the lateral axes. ... For other uses, see Fracture (disambiguation). ... A conchoidal fracture is produced when some types of fine-grained mineral, such as obsidian and flint, are broken. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... Lustre (American English: luster) is a description of the way light interacts with the surface of a crystal, rock or mineral. ... Adamantine is a mineral, often referred to as adamantine spar. ... Adamantine is a mineral, often referred to as adamantine spar. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... A calcite crystal laid upon a paper with some letters showing the double refraction Birefringence, or double refraction, is the decomposition of a ray of light into two rays (the ordinary ray and the extraordinary ray) when it passes through certain types of material, such as calcite crystals, depending on... Dispersion of a light beam in a prism. ... Pleochroism is an optical phenomenon in which grains of a rock appear to be different colors when observed at different angles,under a petrographic microscope. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... Absorption spectroscopy refers to a wide range of techniques where one measures how much light of a particular wavelength (color) is absorbed by a sample. ... The streak (also called powder color) of a mineral is the color of the powder produced when it is dragged across a unweathered surface. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... For other uses, see Density (disambiguation). ... This article or section does not cite any references or sources. ... Look up hardness in Wiktionary, the free dictionary. ... A natural material is any product or physical matter that comes from plants and animals used to make other objects or products. ... Look up material in Wiktionary, the free dictionary. ... Aggregated diamond nanorods, or ADNRs, are an allotrope of carbon believed to be the least compressible material known to humankind, as measured by its isothermal bulk modulus; aggregated diamond nanorods have a modulus of 491 gigapascals (GPa), while a conventional diamond has a modulus of 442 GPa. ... The C60 fullerene in crystalline form Fullerites are the solid-state manifestation of fullerenes and related compounds and materials. ... Dispersion of a light beam in a prism. ... This article does not cite any references or sources. ... Jewelry (the American spelling; spelled jewellery in Commonwealth English) consists of ornamental devices worn by persons, typically made with gems and precious metals. ...


Diamonds are specifically renowned as a material with superlative physical qualities; they make excellent abrasives because they can be scratched only by other diamonds, Borazon, ultrahard fullerite, or aggregated diamond nanorods, which also means they hold a polish extremely well and retain their lustre. Approximately 130 million carats (26,000 kg) are mined annually, with a total value of nearly USD $9 billion, and about 100,000 kg are synthesized annually.[2] An abrasive is a material, often a mineral, that is used to shape or finish (see metal polishing and wood finishing) a workpiece through rubbing which leads to part of the workpiece being worn away. ... Borazon is the third hardest substance that is artificially produced, preceded by aggregated diamond nanorods and man-made diamonds, respectively. ... The C60 fullerene in crystalline form Fullerites are the solid-state manifestation of fullerenes and related compounds and materials. ... In nanotechnology, nanorods are one morphology of nanoscale objects. ... Lustre (American English: luster) is a description of the way light interacts with the surface of a crystal, rock or mineral. ... The carat is a unit of mass used for gems, and equals 200 milligrams or 3. ... The United States dollar is the official currency of the United States. ... One thousand million (1,000,000,000) is the natural number following 999,999,999 and preceding 1,000,000,001. ...


The name diamond derives from the ancient Greek adamas (αδάμας; “invincible”). They have been treasured as gemstones since their use as religious icons in ancient India and usage in engraving tools also dates to early human history.[3][4] Popularity of diamonds has risen since the 19th century because of increased supply, improved cutting and polishing techniques, growth in the world economy, and innovative and successful advertising campaigns. They are commonly judged by the “four Cs”: carat, clarity, color, and cut. Greek ( IPA: or simply IPA: — Hellenic) has a documented history of 3,500 years, the longest of any single language in the Indo-European language family. ... For other uses, see Gemstone (disambiguation). ... Look up icon in Wiktionary, the free dictionary. ... This article tries to compile and classify all the kingdoms of ancient India mentioned in the Sanskrit/Vedic literature. ... Engraving is the practice of incising a design onto a hard, flat surface, by cutting grooves into it. ... // The history of the world, by convention, is human history, from the first appearance of Homo sapiens to the present. ...


Roughly 49% of diamonds originate from central and southern Africa, although significant sources of the mineral have been discovered in Canada, India, Russia, Brazil, and Australia. They are mined from kimberlite and lamproite volcanic pipes, which brought to the surface the diamond crystals from deep in the Earth where the high pressure and temperature enables the formation of the crystals. The mining and distribution of natural diamonds are subjects of frequent controversy such as with concerns over the sale of conflict diamonds (aka blood diamonds) by African paramilitary groups. A world map showing the continent of Africa Africa is the worlds second-largest and second most-populous continent, after Asia. ... Hewn kimberlite core sample from the James Bay Lowlands region of Northern Ontario, Canada. ... Lamproite is a peralkaline volcanic rock. ... Volcanic Pipe Volcanic pipes are subterranean geological structures formed by the violent, supersonic eruption of deep-origin volcanoes. ... A conflict diamond (also called a blood diamond or a war diamond) is a diamond mined in a war zone and sold, usually clandestinely, in order to finance an insurgent or invading armys war efforts. ... Paramilitary designates forces whose function and organization are similar to those of a professional military force, but which are not regarded as having the same status. ...

Contents

Material properties

See also: Crystallographic defects in diamond

A diamond is a transparent crystal of tetrahedrally bonded carbon atoms and crystallizes into the face centered cubic diamond lattice structure. Diamonds have been adapted for many uses because of the material's exceptional physical characteristics. Most notable are its extreme hardness, its high dispersion index, and extremely high thermal conductivity (900 – 2320 W/m K), with a melting point of 3820 K (3547 °C / 6420 °F) and a boiling point of 5100 K (4827 °C / 8720 °F).[5] Naturally occurring diamond has a density ranging from 3.15 to 3.53 g/cm³, with very pure diamond typically extremely close to 3.52 g/cm³. This article addresses the material properties of diamond. ... This article addresses the possible defects of a diamond crystal. ... Transparent glass ball In optics, transparency is the property of allowing light to pass. ... For other uses, see Crystal (disambiguation). ... The tetrahedral-octahedral honeycomb is a tessellation (or honeycomb) in Euclidean 3-space made up of alternating tetrahedra and octahedra. ... The cubic crystal system (or isometric) is a crystal system where the unit cell is in the shape of a cube. ... One unit cell of the diamond cubic crystal structure. ... Dispersion of a light beam in a prism. ... K value redirects here. ... The melting point of a crystalline solid is the temperature range at which it changes state from solid to liquid. ...


Hardness

Diamond is the hardest natural material known to man: Its hardness set to 10 (hardest) on Mohs scale of mineral hardness[6] and having an absolute hardness value of between 90, 167, and 231 gigapascals in various tests. Diamond's hardness has been known since antiquity, and is the source of its name. This article or section does not cite any references or sources. ... The gigapascal, symbol GPa is an SI unit of pressure. ...


The hardest diamonds in the world are from 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 considered to be a product of the crystal growth form, which is single stage growth crystal. 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.[7] The New England region of Australia, here showing Mt Duval Approximate location of New England within New South Wales; red a narrow definition, yellow a broader definition New England is the name given to a region in the north of the state of New South Wales, Australia. ... “NSW” redirects here. ... Crystals are entities of atoms, ions or even polymer strings in which the subunits (i. ...


The hardness of diamonds contributes to its suitability as a gemstone. Because it can only be scratched by other diamonds, it maintains its polish extremely well, keeping its luster over long whiles. 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 an engagement ring or wedding ring, which are often worn every day. For other uses, see Gemstone (disambiguation). ... A yellow gold wedding ring and a single-diamond, gold-banded engagement ring. ... A wedding ring or wedding band consists of a precious metal ring, in certain countries (UK, USA, Brazil) worn on the base of the left ring finger – the fourth finger (counting from the thumb) of the left hand. ...


Industrial use of diamonds has historically been associated with their hardness; this property makes diamond the ideal material for cutting and grinding tools. As the hardest known naturally-occurring material, diamond can be used to polish, cut, or wear away any material, including other diamonds. However, diamond is a poor choice for machining ferrous alloys at high speeds. At the high temperatures created by high speed machining, carbon is soluble in iron, leading to greatly increased wear on diamond tools as compared to other alternatives. Common industrial adaptations of this ability include diamond-tipped drill bits and saws, or use of diamond powder as an abrasive. Industrial-grade diamonds are either unsuitable for use as gems or synthetically produced, which lowers their value and makes their use economically feasible. An abrasive is a material, often a mineral, that is used to shape or finish (see metal polishing and wood finishing) a workpiece through rubbing which leads to part of the workpiece being worn away. ...


Electrical conductivity

Other specialized applications also exist or are being developed, including use as semiconductors: some blue diamonds are natural semiconductors, in contrast to most other diamonds, which are excellent electrical insulators.[6] A semiconductor is a solid whose electrical conductivity is in between that of a conductor and that of an insulator, and can be controlled over a wide range, either permanently or dynamically. ... This article or section is in need of attention from an expert on the subject. ...


Toughness

Toughness relates to a material's ability to resist breakage from forceful impact. The toughness of natural diamond has been measured as 3.4 MN m-3/2,[8] which is good compared to other gemstones, but poor compared to most engineering materials. As with any material, the macroscopic geometry of a diamond contributes to its resistance to breakage. Diamond is therefore more fragile in some orientations than others. In materials science and metallurgy, toughness is the resistance to fracture of a material when stressed. ...


Color

Diamonds can occur in nearly any color, though yellow and brown are by far the most common.[6] "Black" 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 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.[6] The Gemological Institute of America (GIA) classifies low saturation yellow and brown diamonds as diamonds in the normal color range, and applies a grading scale from 'D' (colorless) to 'Z' (light yellow). In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... A carbon flaw is a blemish present within a diamond crystalline form of carbon, usually seen as a black spot. ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... The Gemological Institute of America, or GIA, is a non-profit institute dedicated to research and education in the field of gemology. ...


A blue diamond recently fetched nearly $8 million. The blue hue was a result of trace amounts of boron in the stone's crystal structure.[9]


Identification

Diamonds can be identified via their high thermal conductivity. Their high refractive index is also indicative, but other materials have similar refractivity. Diamonds do cut glass, but other materials above glass on Mohs scale such as quartz do also. Diamonds easily scratch other diamonds, but this damages both diamonds.[10] Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ...


Natural history

Formation

The formation of natural diamond requires very specific conditions. Diamond formation requires exposure of carbon-bearing materials to high pressure, ranging approximately between 45 and 60 kilobars,[11] but at a comparatively low temperature range between approximately 1652–2372 °F (900–1300 °C).[11] These conditions are known to be met in two places on Earth; in the lithospheric mantle below relatively stable continental plates, and at the site of a meteorite strike. This article is about pressure in the physical sciences. ... For other uses, see Temperature (disambiguation). ... The tectonic plates of the Lithosphere on Earth. ... The Continental Crust is the layer of granitic and sedimentary rock which forms the continents and the areas of shallow seabed close to their shores, known as continental shelves. ... Willamette Meteorite A meteorite is a natural object originating in outer space that survives an impact with the Earths surface without being destroyed. ...


Diamonds formed in cratons

The conditions for diamond formation to happen in the lithospheric mantle occur at considerable depth corresponding to the aforementioned requirements of temperature and pressure. These depths are estimated to be in between 140–190 kilometers (90–120 miles)[11][6] though occasionally diamonds have crystallized at depths of 300-400 km (180-250 miles) as well.[12] The rate at which temperature changes with increasing depth into the Earth varies greatly in different parts of the Earth. In particular, under oceanic plates the temperature rises more quickly with depth, beyond the range required for diamond formation at the depth required.[11] The correct combination of temperature and pressure is only found in the thick, ancient, and stable parts of continental plates where regions of lithosphere known as cratons exist.[11] Long residence in the cratonic lithosphere allows diamond crystals to grow larger. penis, hahaha big long penis. ... The Continental Crust is the layer of granitic and sedimentary rock which forms the continents and the areas of shallow seabed close to their shores, known as continental shelves. ... World geologic provinces. ...

The slightly misshapen octahedral shape of this rough diamond crystal in matrix is typical of the mineral. Its lustrous faces also indicate that this crystal is from a primary deposit.
The slightly misshapen octahedral shape of this rough diamond crystal in matrix is typical of the mineral. Its lustrous faces also indicate that this crystal is from a primary deposit.

Through studies of carbon isotope ratios (similar to the methodology used in carbon dating, except with the stable isotopes C-12 and C-13), it has been shown that the carbon found in diamonds comes from both inorganic and organic sources. Some diamonds, known as harzburgitic, are formed from inorganic carbon originally found deep in the Earth's mantle. In contrast, eclogitic diamonds contain organic carbon from organic detritus that has been pushed down from the surface of the Earth's crust through subduction (see plate tectonics) before transforming into diamond.[6] These two different source carbons have measurably different 13C:12C ratios. Diamonds that have come to the Earth's surface are generally very old, ranging from under 1 billion to 3.3 billion years old. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... For other uses, see Isotope (disambiguation). ... Radiocarbon dating is the use of the naturally occurring isotope of carbon-14 in radiometric dating to determine the age of organic materials, up to ca. ... Stable isotopes are chemical isotopes that are not radioactive. ... Peridotite xenolith from San Carlos, southwestern United States. ... Earth cutaway from core to exosphere. ... Eclogite is a coarse-grained, mafic-to-ultramafic grouping of metamorphic rocks of special interest on account of the variety of minerals they contain and their microscopic structures and geological relationships. ... Detritus may refer to: In geology, detritus is the name for loose fragments of rock that have been worn away by erosion. ... Earth cutaway from core to exosphere. ... The Juan de Fuca plate sinks below the North America plate at the Cascadia subduction zone. ... The tectonic plates of the world were mapped in the second half of the 20th century. ... One thousand million (1,000,000,000) is the natural number following 999,999,999 and preceding 1,000,000,001. ...


Diamonds occur most often as euhedral or rounded octahedra and twinned octahedra known as macles or maccles. As diamond's crystal structure has a cubic arrangement of 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. Sometimes they are found grown together or form double "twinned" crystals grown together at the surfaces of the octahedron. These different shapes and habits of the diamonds result from differing external circumstances. Diamonds (especially those with rounded crystal faces) are commonly found coated in nyf, an opaque gum-like skin.[13] Euhedral refers to well formed crystals with sharp easily recognised faces. ... An octahedron (plural: octahedra) is a polyhedron with eight faces. ... It has been suggested that twin boundary be merged into this article or section. ... Facets are flat faces on geometric shapes. ... Three dimensions A cube (or hexahedron) is a Platonic solid composed of six square faces, with three meeting at each vertex. ... An octahedron (plural: octahedra) is a polyhedron with eight faces. ... A colored model Net (polyhedron) The rhombicosidodecahedron, or small rhombicosidodecahedron, is an Archimedean solid. ... A tetrakis hexahedron is a Catalan solid which looks a bit like an overinflated cube. ... A disdyakis dodecahedron, or hexakis octahedron, is the Catalan solid whose Archimedean dual is the truncated cuboctahedron. ...


Diamonds and meteorite impact craters

Diamonds can also form in other natural high-pressure events. Very small diamonds, known as microdiamonds or nanodiamonds, have been found in meteorite impact craters. Such impact events create shock zones of high pressure and temperature suitable for diamond formation. Impact-type microdiamonds can be used as one indicator of ancient impact craters.[6] Willamette Meteorite A meteorite is a natural object originating in outer space that survives an impact with the Earths surface without being destroyed. ... Tycho crater on Earths moon. ... Wikipedia does not yet have an article with this exact name. ...


Extraterrestrial diamonds

Not all diamonds found on earth originated here. A type of diamond called carbonado diamond that is found in South America and Africa was deposited there via an asteroid impact (not formed from the impact) about 3 billion years ago.[14][15] These diamonds formed in the intrastellar environment. Carbonado is a natural polycrystalline diamond found in alluvial deposits in the Central African Republic and Brazil. ...


Presolar grains in many meteorites found on earth contain nanodiamonds of extraterrestrial origin, probably formed in supernovas. Presolar grains are tiny crystalline grains found in the fine-grained matrix of primitive meteorites, and are assumed to be older than the solar system. ... For other uses, see Supernova (disambiguation). ...


Surfacing

Schematic diagram of a volcanic pipe
Schematic diagram of a volcanic pipe

Diamond-bearing rock is brought close to the surface through deep-origin volcanic eruptions. The magma for such a volcano must originate at a depth where diamonds can be formed,[6] 150 km (90 miles) deep or more (three times or more the depth of source magma for most volcanoes); this is a relatively rare occurrence. These typically small surface volcanic craters extend downward in formations known as volcanic pipes.[6] The pipes contain material that was transported toward the surface by volcanic action, but was not ejected before the volcanic activity ceased. During eruption these pipes are open to the surface, resulting in open circulation; many xenoliths of surface rock and even wood and/or fossils are found in volcanic pipes. Diamond-bearing volcanic pipes are closely related to the oldest, coolest regions of continental crust (cratons). This is because cratons are very thick, and their lithospheric mantle extends to great enough depth that diamonds are stable. Not all pipes contain diamonds, and even fewer contain enough diamonds to make mining economically viable. Image File history File linksMetadata Download high resolution version (795x801, 331 KB) Volcanic pipe File links The following pages link to this file: Diamond User:Asbestos/Images Volcanic pipe Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... Image File history File linksMetadata Download high resolution version (795x801, 331 KB) Volcanic pipe File links The following pages link to this file: Diamond User:Asbestos/Images Volcanic pipe Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. ... Cleveland Volcano in the Aleutian Islands of Alaska photographed from the International Space Station For other uses, see Volcano (disambiguation). ... Magma is molten rock located beneath the surface of the Earth (or any other terrestrial planet), and which often collects in a magma chamber. ... Volcanic Pipe Volcanic pipes are subterranean geological structures formed by the violent, supersonic eruption of deep-origin volcanoes. ... A xenolith A xenolith (Greek: foreign rock) is a rock fragment which becomes enveloped in a larger rock during the latters development and hardening. ... For other uses, see Fossil (disambiguation). ... The thickness of the Earths crust (km). ... World geologic provinces. ... The tectonic plates of the Lithosphere on Earth. ...


The magma in volcanic pipes is usually one of two characteristic types, which cool into igneous rock known as either kimberlite or lamproite.[6] The magma itself does not contain diamond; instead, it acts as an elevator that carries deep-formed rocks (xenoliths), minerals (xenocrysts), and fluids upward. These rocks are characteristically rich in magnesium-bearing olivine, pyroxene, and amphibole minerals[6] which are often altered to serpentine by heat and fluids during and after eruption. Certain indicator minerals typically occur within diamondiferous kimberlites and are used as mineralogic tracers by prospectors, who follow the indicator trail back to the volcanic pipe which may contain diamonds. These minerals are rich in chromium (Cr) or titanium (Ti), elements which impart bright colors to the minerals. The most common indicator minerals are chromian garnets (usually bright red Cr-pyrope, and occasionally green ugrandite-series garnets), eclogitic garnets, orange Ti-pyrope, red high-Cr spinels, dark chromite, bright green Cr-diopside, glassy green olivine, black picroilmenite, and magnetite.[6] Kimberlite deposits are known as blue ground for the deeper serpentinized part of the deposits, or as yellow ground for the near surface smectite clay and carbonate weathered and oxidized portion. Volcanic rock on North America Plutonic rock on North America Igneous rocks (etymology from latin ignis, fire) are rocks formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... Hewn kimberlite core sample from the James Bay Lowlands region of Northern Ontario, Canada. ... Lamproite is a peralkaline volcanic rock. ... A xenolith A xenolith (Greek: foreign rock) is a rock fragment which becomes enveloped in a larger rock during the latters development and hardening. ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... The mineral olivine (also called chrysolite and, when gem-quality, peridot) is a magnesium iron silicate with the formula (Mg,Fe)2SiO4. ... Figure 1:Mantle-peridotite xenolith with green peridot olivine and black pyroxene crystals from San Carlos Indian Reservation, Gila Co. ... For the logical fallacy, see Amphibology. ... For other uses, see Serpentine (disambiguation). ... General Name, symbol, number chromium, Cr, 24 Chemical series transition metals Group, period, block 6, 4, d Appearance silvery metallic Standard atomic weight 51. ... General Name, symbol, number titanium, Ti, 22 Chemical series transition metals Group, period, block 4, 4, d Appearance silvery metallic Standard atomic weight 47. ... Garnet is a group of minerals that have been used since the Bronze Age as gemstones and abrasives. ... The pyrope is a garnet. ... The spinels are any of a class of minerals which crystallize in the isometric system with an octahedral habit. ... Chromite, iron magnesium chromium oxide: (Fe,Mg)Cr2O4, is an oxide mineral belonging to the spinel group. ... Diopside Diopside is a monoclinic pyroxene mineral with composition MgCaSi2O6. ... The mineral olivine (also called chrysolite and, when gem-quality, peridot) is a magnesium iron silicate with the formula (Mg,Fe)2SiO4. ... Ilmenite is a weakly magnetic iron-black or steel-gray mineral found in metamorphic and igneous rocks. ... Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. ... It has been suggested that this article or section be merged with Clay. ... For other uses, see Clay (disambiguation). ... Weathering is the decomposition of rocks, soils and their minerals through direct contact with the air. ... The most fundamental reactions in chemistry are the redox processes. ...


Once diamonds have been transported to the surface by magma in a volcanic pipe, they may erode out and be distributed over a large area. A volcanic pipe containing diamonds is known as a primary source of diamonds. Secondary sources of diamonds include all areas where a significant number of diamonds, eroded out of their kimberlite or lamproite matrix, accumulate because of water or wind action. These include alluvial deposits and deposits along existing and ancient shorelines, where loose diamonds tend to accumulate because of their approximate size and density. Diamonds have also rarely been found in deposits left behind by glaciers (notably in Wisconsin and Indiana); however, in contrast to alluvial deposits, glacial deposits are not known to be of significant concentration and are therefore not viable commercial sources of diamond. For morphological image processing operations, see Erosion (morphology). ... Alluvium (from the Latin, alluvius, from alluere, to wash against) is soil or sediments deposited by a river or other running water. ... Official language(s) None Capital Madison Largest city Milwaukee Area  Ranked 23rd  - Total 65,498 sq mi (169,790 km²)  - Width 260 miles (420 km)  - Length 310 miles (500 km)  - % water 17  - Latitude 42° 30′ N to 47° 05′ N  - Longitude 86° 46′ W to 92° 53′ W Population  Ranked... For other uses, see Indiana (disambiguation). ... An alluvial deposit is an accumulation of alluvium (sediment), sometimes containing valuable ore and gemstones, or simply consisting of gravel, sand, or clay, in the bed or former bed of a river. ...


History and gemological characteristics

Main article: Diamond (gemstone)

Diamonds are thought to have been first recognized and mined in India (Golconda being one of them), where significant alluvial deposits of the stone could then be found along the rivers Penner, Krishna and Godavari. Diamonds have been known in India for at least 3000 years but most likely 6000 years.[16] The most familiar usage of diamonds today is as gemstones used for adornment a usage which dates back into antiquity. The dispersion of white light into spectral colors, is the primary gemological characteristic of gem diamonds. In the twentieth century, experts in the field of gemology have developed methods of grading diamonds and other gemstones based on the characteristics most important to their value as a gem. Four characteristics, known informally as the four Cs, are now commonly used as the basic descriptors of diamonds: these are carat, cut, color, and clarity. As a gemstone, diamond is perhaps the most valued. ... Golconda fort overlooking Hyderabad Golkonda, also Golconda, a ruined city of south-central India and west of Hyderabad, capital of ancient Hyderabad state (c. ... Many see natural beauty in the folded petals of a rose This page is about the pleasant phenomenon. ... Antiquity means different things: Generally it means ancient history, and may be used of any period before the Middle Ages. ... Dispersion can mean any of several things: A phenomenon that causes the separation of a wave into components of varying frequency. ... A spectral color is a color that is evoked by the optical spectrum; every wavelength of light yields a different spectral color, in a continuous spectrum. ... Gemology (gemmology outside the United States) is the science, art and profession of identifying and evaluating gemstones. ...


The diamond industry

See also: Diamonds as an investment
A round brilliant cut diamond set in a ring
A round brilliant cut diamond set in a ring

The diamond industry can be broadly separated into two basically distinct categories: one dealing with gem-grade diamonds and another for industrial-grade diamonds. While a large trade in both types of diamonds exists, the two markets act in dramatically different ways. This article discusses the use of diamonds as an investment. ... Diamond Ring Photograph taken by CrucifiedChrist and licensed under File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A scattering of brilliant cut diamonds shows off the many reflecting facets. ...


Gem diamond industry

Main article: Diamond (gemstone)

A large trade in gem-grade diamonds exists. Unlike precious metals such as gold or platinum, gem diamonds do not trade as a commodity: there is a substantial mark-up in the sale of diamonds, and there is not a very active market for resale of diamonds. One hallmark of the trade in gem-quality diamonds is its remarkable concentration: wholesale trade and diamond cutting is limited to a few locations (most importantly Antwerp, London, New York, Tel Aviv, Amsterdam and Surat), and a single company—De Beers—controls a significant proportion of the trade in diamonds. They are based in Johannesburg, South Africa and London, England. As a gemstone, diamond is perhaps the most valued. ... For other uses, see Gemstone (disambiguation). ... For the CSI episode of the same name, see Precious Metal (CSI episode). ... GOLD refers to one of the following: GOLD (IEEE) is an IEEE program designed to garner more student members at the university level (Graduates of the Last Decade). ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ... This article does not cite any references or sources. ... For other uses, see Antwerp (disambiguation). ... This article is about the capital of England and the United Kingdom. ... New York, New York and NYC redirect here. ... Tel-Aviv was founded on empty dunes north of the existing city of Jaffa. ... For other uses, see Amsterdam (disambiguation). ... The tone or style of this article or section may not be appropriate for Wikipedia. ... De Beers, founded in South Africa by Cecil Rhodes, comprises companies involved in rough diamond exploration, diamond mining and diamond trading. ... This article is about the city in South Africa. ... This article is about the capital of England and the United Kingdom. ... For other uses, see England (disambiguation). ...


The production and distribution of diamonds is largely consolidated in the hands of a few key players, and concentrated in traditional diamond trading centers. The most important being Antwerp, where 80% of all rough diamonds, 50% of all cut diamonds and more than 50% of all rough, cut and industrial diamonds combined are handled. This makes Antwerp the de facto 'world diamond capital'. New York, however, along with the rest of the United States, is where almost 80% of the world's diamonds are sold, including at auction. Also, the largest and most unusually shaped rough diamonds end up in New York. The De Beers company, as the world's largest diamond miner holds a clearly dominant position in the industry, and has done so since soon after its founding in 1888 by the British imperialist Cecil Rhodes. De Beers owns or controls a significant portion of the world's rough diamond production facilities (mines) and distribution channels for gem-quality diamonds. The company and its subsidiaries own mines that produce some 40 percent of annual world diamond production. At one time it was thought over 80 percent of the world's rough diamonds passed through the Diamond Trading Company (DTC, a subsidiary of De Beers) in London, but presently the figure is estimated at less than 50 percent. For other uses, see Antwerp (disambiguation). ... This article is about the state. ... Cecil Rhodes Cecil John Rhodes, PC, DCL, (July 5, 1853 – March 26, 1902[1]) was a British-born South African businessman, mining magnate, and politician. ... Chuquicamata, the second largest open pit copper mine in the world, Chile. ... Wikibooks has more about this subject: Marketing Distribution is one of the 4 aspects of marketing. ... The Diamond Trading Company (DTC) is a London-based subsidiary of the De Beers Group, specializing in the sale and marketing of rough (uncut) diamonds. ...


The De Beers diamond advertising campaign is acknowledged as one of the most successful and innovative campaigns in history. N. W. Ayer & Son, the advertising firm retained by De Beers in the mid-20th century, succeeded in reviving the American diamond market and opened up new markets, even in countries where no diamond tradition had existed before. N.W. Ayer's multifaceted marketing campaign included product placement, advertising the diamond itself rather than the De Beers brand, and building associations with celebrities and royalty. This coordinated campaign has lasted decades and continues today; it is perhaps best captured by the slogan "a diamond is forever". De Beers, founded in South Africa by Cecil Rhodes, comprises companies involved in rough diamond exploration, diamond mining and diamond trading. ... N. W. Ayer & Son was the first advertising agency in the United States, founded in Philadelphia, Pennsylvania in 1869. ... Wikibooks has more about this subject: Marketing Product placement advertisements are promotional ads placed by marketers using real commercial products and services in media, where the presence of a particular brand is the result of an economic exchange. ... Look up slogan in Wiktionary, the free dictionary. ...


Further down the supply chain, members of The World Federation of Diamond Bourses (WFDB) act as a medium for wholesale diamond exchange, trading both polished and rough diamonds. The WFDB consists of independent diamond bourses in major cutting centres such as Tel Aviv, Antwerp, Johannesburg and other cities across the USA, Europe and Asia. World Federation of Diamond Bourses, founded in 1947, was created to unite and to provide bourses trading in rough and polished diamonds and precious stones, with a common set of trading practices. ...


In 2000, the WFDB and The International Diamond Manufacturers Association established the World Diamond Council to prevent the trading of diamonds used to fund war and inhumane acts. The World Diamond Council (also known during its prototype period as the International Diamond Council) is an organisation consisting of representatives from diamond manufacturing and diamond trading companies. ...


WFDB's additional activities also include sponsoring the World Diamond Congress every two years, as well as the establishment of the International Diamond Council (IDC) to oversee diamond grading. World Diamond Congress is made up of representation from the World Federation of Diamond Bourses and the International Diamond Manufacturers Association. ... The World Diamond Council (also known during its prototype period as the International Diamond Council) is an organisation consisting of representatives from diamond manufacturing and diamond trading companies. ...


Industrial diamond industry

The market for industrial-grade diamonds operates much differently from its gem-grade counterpart. Industrial diamonds are valued mostly for their hardness and heat conductivity, making many of the gemological characteristics of diamond, including clarity and color, mostly irrelevant. This helps explain why 80% of mined diamonds (equal to about 100 million carats or 20,000 kg annually), unsuitable for use as gemstones and known as bort, are destined for industrial use. In addition to mined diamonds, synthetic diamonds found industrial applications almost immediately after their invention in the 1950s; another 3 billion carats (600 metric tons) of synthetic diamond is produced annually for industrial use. Bort or boart is a term used in the diamond industry to refer to shards of gem-grade/quality diamonds. ... A collection of colorless cultured diamonds grown by Apollo Diamond, Inc. ... A tonne or metric ton (symbol t), sometimes referred to as a metric tonne, is a measurement of mass equal to 1,000 kilograms. ...


The dominant industrial use of diamond is in cutting, drilling, grinding, and polishing. Most uses of diamonds in these technologies do not require large diamonds; in fact, most diamonds that are gem-quality except for their small size, can find an industrial use. Diamonds are embedded in drill tips or saw blades, or ground into a powder for use in grinding and polishing applications. Specialized applications include use in laboratories as containment for high pressure experiments (see diamond anvil), high-performance bearings, and limited use in specialized windows. Pressure experiments are experiments performed at pressures lower or higher than atmospheric pressure, called low-pressure experiments and high-pressure experiments, respectively. ... A diamond anvil, more properly a diamond anvil cell (DAC), is a device used by physicists to exert extreme pressures on a material. ... A bearing is a device to permit constrained relative motion between two parts, typically rotation or linear movement. ... It has been suggested that window frames be merged into this article or section. ...


With the continuing advances being made in the production of synthetic diamonds, future applications are beginning to become feasible. Garnering much excitement is the possible use of diamond as a semiconductor suitable to build microchips from, or the use of diamond as a heat sink in electronics. A semiconductor is a solid whose electrical conductivity is in between that of a conductor and that of an insulator, and can be controlled over a wide range, either permanently or dynamically. ... Integrated circuit of Atmel Diopsis 740 System on Chip showing memory blocks, logic and input/output pads around the periphery Microchips with a transparent window, showing the integrated circuit inside. ... CPU heat sink with fan attached A heat sink (or heatsink) is an environment or object that absorbs and dissipates heat from another object using thermal contact (either direct or radiant). ... This article is about the engineering discipline. ...


Diamond supply chain

See also: List of diamond mines

The diamond supply chain is controlled by a limited number of powerful businesses, and is also highly concentrated in a small number of locations around the world. There are a limited number of commercially viable diamond mines currently operating in the world. ...


Mining, Sources and Production

Only a very small fraction of the diamond ore consists of actual diamonds. The ore is crushed, during which care has to be taken in order to prevent larger diamonds from being destroyed in this process and subsequently the particles are sorted by density. Today, diamonds are located in the diamond-rich density fraction with the help of X-ray fluorescence, after which the final sorting steps are done by hand. Before the use of X-rays became commonplace, the separation was done with grease belts; diamonds have a stronger tendency to stick to grease than the other minerals in the ore. A Philips PW1606 X-ray fluorescence spectrometer with automated sample feed in a cement plant quality control laboratory X-ray fluorescence (XRF) is the emission of characteristic secondary (or fluorescent) X-rays from a material that has been excited by bombarding with high-energy X-rays or gamma rays. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz...


Historically diamonds were known to be found only in alluvial deposits in southern India.[17] India led the world in diamond production from the time of their discovery in approximately the 9th century BCE[18][16] to the mid-18th century AD, but the commercial potential of these sources had been exhausted by the late 18th century and at that time India was eclipsed by Brazil where the first non-Indian diamonds was found in 1725.[16] South India is a geographic and linguistic-cultural region of India. ...


Diamond production of primary deposits (kimberlites and lamproites) only started in the 1870's after the discovery of the Diamond fields in South Africa. Production has increased over time and now an accumulated total of 4.5 billion carats have been mined since that date.[19] Interestingly 20% of that amount has been mined in the last 5 years alone and during the last ten years, 9 new mines have started production while 4 more are awaiting opening soon. Most of these mines are located in Canada, Zimbabwe, Angola, and one in Russia.[19]


While no commercial diamond production exists in the US, Arkansas and Colorado are the only states to have a verifiable source of diamonds.[20] United States may refer to: Places: United States of America SS United States, the fastest ocean liner ever built. ... Official language(s) English Capital Little Rock Largest city Little Rock Largest metro area Little Rock Metropolitan Area Area  Ranked 29th  - Total 53,179 sq mi (137,002 km²)  - Width 239 miles (385 km)  - Length 261 miles (420 km)  - % water 2. ... Official language(s) English Capital Denver Largest city Denver Largest metro area Denver-Aurora Metro Area Area  Ranked 8th  - Total 104,185 sq mi (269,837 km²)  - Width 280 miles (451 km)  - Length 380 miles (612 km)  - % water 0. ...


Today, most commercially viable diamond deposits are in Russia, Botswana, Australia and the Democratic Republic of Congo.[21] In 2005, Russia produced almost one-fifth of the global diamond output, reports the British Geological Survey. Australia boasts the richest diamondiferous pipe with production reaching peak levels of 42 Mct per year in the 1990's[20] The British Geological Survey is a publicly-funded body which aims to advance geoscientific knowledge of the United Kingdom landmass and its continental shelf by means of systematic surveying, monitoring and research. ...


There are also commercial deposits being actively mined in the Northwest Territories of Canada, Siberia (mostly in Yakutia territory, for example Mir pipe and Udachnaya pipe), Brazil, and in Northern and Western Australia. Diamond prospectors continue to search the globe for diamond-bearing kimberlite and lamproite pipes. For the former United States territory, see Northwest Territory. ... This article is about Siberia as a whole. ... The Sakha (Yakutia) Republic (Russian: ; Yakut: Саха Республиката) is a federal subject of Russia (a republic). ... Mir Mine (Russian: ; English: kimberlite diamond pipe Peace) is an abandoned open pit diamond mine located in Mirny, Eastern Siberia. ... View of the Udachnaya open pit. ... Hewn kimberlite core sample from the James Bay Lowlands region of Northern Ontario, Canada. ... Lamproite is a peralkaline volcanic rock. ...

Diamond output in 2005
Diamond output in 2005

Image File history File links Size of this preview: 800 × 351 pixelsFull resolution (1425 × 625 pixel, file size: 59 KB, MIME type: image/png)This bubble map shows the global distribution of diamond output in 2005 as a percentage of the top producer (Russia - 38,000,000 carats). ... Image File history File links Size of this preview: 800 × 351 pixelsFull resolution (1425 × 625 pixel, file size: 59 KB, MIME type: image/png)This bubble map shows the global distribution of diamond output in 2005 as a percentage of the top producer (Russia - 38,000,000 carats). ...

'Blood' diamonds

Main article: Blood diamond

In some of the more politically unstable central African and west African countries, revolutionary groups have taken control of diamond mines, using proceeds from diamond sales to finance their operations. Diamonds sold through this process are known as conflict diamonds or blood diamonds. In response to public concerns that their diamond purchases were contributing to war and human rights abuses in central Africa and West Africa, the United Nations, the diamond industry and diamond-trading nations introduced the Kimberley Process in 2002, which is aimed at ensuring that conflict diamonds do not become intermixed with the diamonds not controlled by such rebel groups, by providing documentation and certification of diamond exports from producing countries to ensure that the proceeds of sale are not being used to fund criminal or revolutionary activities. Although the Kimberley Process has been moderately successful in limiting the number of conflict diamonds entering the market, conflict diamonds smuggled to market continue to persist to some degree (approx. 2–3% of diamonds traded today are possible conflict diamonds[22]). According to the 2006 book The Heartless Stone, two major flaws still hinder the effectiveness of the Kimberley Process: the relative ease of smuggling diamonds across African borders and giving phony histories, and the violent nature of diamond mining in nations which are not in a technical state of war and whose diamonds are therefore considered "clean."[23] Panning for diamonds in Sierra Leone. ... There are a limited number of commercially viable diamond mines currently operating in the world. ... A human rights abuse is abuse of people in a way that violates any fundamental human rights. ...  Western Africa (UN subregion)  Maghreb[1] West Africa or Western Africa is the westernmost region of the African continent. ... UN and U.N. redirect here. ... The Kimberley Process Certification Scheme (KPCS) is a scheme designed to prevent conflict diamonds (also known as blood diamonds) entering the mainstream rough diamond market. ...


The Canadian Government has setup a body known as Canadian Diamond Code of Conduct: ([1]) to help authenticate Canadian Diamonds. This is a very stringent tracking system of diamonds and helps protect the 'conflict free' label of Canadian diamonds.


Currently, gem production totals nearly 30 million carats (6,000 kg) of cut and polished stones annually, and over 100 million carats (20,000 kg) of mined diamonds are sold for industrial use each year, as are about 100,000 kg of synthesized diamond.


Distribution

The Diamond Trading Company, or DTC, is a subsidiary of De Beers and markets rough diamonds produced both by De Beers mines and other mines from which it purchases rough diamond production. Once purchased by sightholders, diamonds are cut and polished in preparation for sale as gemstones. The cutting and polishing of rough diamonds is a specialized skill that is concentrated in a limited number of locations worldwide. Traditional diamond cutting centers are Antwerp, Amsterdam, Johannesburg, New York, and Tel Aviv. Recently, diamond cutting centers have been established in China, India, and Thailand. Cutting centers with lower cost of labor, notably Surat in Gujarat, India, handle a larger number of smaller carat diamonds, while smaller quantities of larger or more valuable diamonds are more likely to be handled in Europe or North America. The recent expansion of this industry in India, employing low cost labor, has allowed smaller diamonds to be prepared as gems in greater quantities than was previously economically feasible. The Diamond Trading Company (DTC) is a London-based subsidiary of the De Beers Group, specializing in the sale and marketing of rough (uncut) diamonds. ... For other uses, see Antwerp (disambiguation). ... For other uses, see Amsterdam (disambiguation). ... This article is about the city in South Africa. ... Midtown Manhattan, looking north from the Empire State Building, 2005 New York City (officially named the City of New York) is the most populous city in the state of New York and the entire United States. ... Tel-Aviv was founded on empty dunes north of the existing city of Jaffa. ... The tone or style of this article or section may not be appropriate for Wikipedia. ... This article is for the Indian state. ... For other uses, see Europe (disambiguation). ... North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ...


Diamonds which have been prepared as gemstones are sold on diamond exchanges called bourses. There are 26 registered diamond bourses.[24] This is the final tightly controlled step in the diamond supply chain; wholesalers and even retailers are able to buy relatively small lots of diamonds at the bourses, after which they are prepared for final sale to the consumer. Diamonds can be sold already set in jewelry, or as is increasingly popular, sold unset ("loose"). According to the Rio Tinto Group, in 2002 the diamonds produced and released to the market were valued at US$9 billion as rough diamonds, US$14 billion after being cut and polished, US$28 billion in wholesale diamond jewelry, and retail sales of US$57 billion. [2] Rio Tinto is a multinational mining and resources group founded originally in 1873. ... Jewelry (the American spelling; spelled jewellery in Commonwealth English) consists of ornamental devices worn by persons, typically made with gems and precious metals. ...


Synthetics, simulants, and enhancements

Natural diamonds have formed naturally within the earth. Synthetic diamonds are created by a man-made process. A diamond simulant is defined as a non-diamond material that is used to simulate the appearance of a diamond. Diamond-simulant gems are often referred to as diamante. A collection of colorless cultured diamonds grown by Apollo Diamond, Inc. ... This article addresses the many imitations of diamond. ... This article addresses treatments designed to enhance the gemological characteristics of diamond. ... A collection of colorless cultured diamonds grown by Apollo Diamond, Inc. ... Due to its low cost and close visual likeness to diamond, cubic zirconia has remained the most gemologically and economically important diamond simulant since 1976. ... Diamante can refer to Fra Diamante, Italian painter Juan Bautista Diamante, Spanish playwright A Department of Argentina, and its capital The car Mitsubishi Diamante A faceted glass bead A form of poetry This is a disambiguation page—a list of articles associated with the same title. ...


The gemological and industrial uses of diamond have created a large demand for rough stones. The demand for industrial diamonds has long been satisfied in large part by synthetic diamonds, which have been manufactured by various processes for more than half a century. However, in recent years it has become possible to produce gem-quality synthetic diamonds of significant size.[25] A collection of colorless cultured diamonds grown by Apollo Diamond, Inc. ...


The majority of commercially available synthetic diamonds are yellow in color and produced by so called High Pressure High Temperature (HPHT) processes.[26] The yellow color is caused by Nitrogen impurities. Other colors may also be reproduced such as blue, green or pink which are a result of the addition of Boron or from irradiation after synthetisation.[27]


At present the annual production of gem quality synthetic diamonds is only a few thousand carats, whereas the total production of natural diamonds is around 120 million carats. Although the production of colorless synthetic diamonds is dwarfed by that of natural diamonds, one can only find one fancy colored diamond for every 10.000 colorless ones. Since almost the complete production of synthetic diamonds consists of fancy diamonds, there is a high probability that the larger fancy colored diamonds (over 1.5 carats) will be synthetic.[28]


Currently, trained gemologists can also distinguish between natural diamonds from synthetic diamonds. Although it has been claimed that synthetic diamonds are so perfect that it is virtually impossible to distinguish them from natural diamonds, this is not the case. Depending on the type of diamonds (either HPHT produced or CVD produced) and the color of the diamond (colored, D-Z color range or D-J color range) several methods of identification are at the disposal of a gemologist or gemlab: CVD diamonds can be identified through their orange fluorescence, D-J colored diamonds can be screened through the Swiss Gemological Organization's (SSEF)[29] Diamond Spotter and stones in the D-Z color range can be identified through the DiamondSure UV/visible spectrometer which is a tool developed by De Beers.[30]


A diamond's gem quality, which is not as dependent on material properties as industrial applications, has invited both imitation and the invention of procedures to enhance the gemological properties of natural diamonds. Materials which have similar gemological characteristics to diamond but are not mined or synthetic diamond are known as diamond simulants. The most familiar diamond simulant to most consumers is cubic zirconia (commonly abbreviated as CZ); recently moissanite has also gained popularity and has often been mischaracterized as a diamond simulant, although it is sold and retailed as a replacement for diamond. Both CZ and moissanite are synthetically produced. However, CZ is a diamond simulant. Diamond enhancements are specific treatments, performed on natural diamonds (usually those already cut and polished into a gem), which are designed to better the gemological characteristics of the stone in one or more ways. These include laser drilling to remove inclusions, application of sealants to fill cracks, treatments to improve a white diamond's color grade, and treatments to give fancy color to a white diamond. A round brilliant-cut cubic zirconia Cubic zirconia (or CZ), the cubic crystalline form of zirconium dioxide (ZrO2), is a mineral that is widely synthesized for use as a diamond simulant. ... Moissanite is a trade name given to silicon carbide (chemical formula SiC) for use in the gem business. ...


Currently, trained gemologists with appropriate equipment are able to distinguish natural diamonds from simulant diamonds, and they can identify all enhanced natural diamonds. Coatings are more and more used to give a diamond simulant such as Cubic Zirconia a more "Diamond like" appearance. One such substance, which is heavily advertised, is what scientists refer to as "diamond-like carbon". This is an amorphous carbonaceous material that has some physical properties which are similar to that of the diamond. Advertising suggests (righfully so or not) that such a coating would transfer some of these diamond-like properties to the coated stone, hence enhancing the diamond simulant. However, modern techniques such as Raman Spectroscopy should easily identify such as treatment.[31]


Producing large synthetic diamonds threatens the business model of the diamond industry, and the ultimate effect of the ready availability of gem-quality diamonds at low cost in the future is hard to predict at this time.


The screening machine use for referring treated or enhanced diamonds as well as synthetics is the DiamondSure, and the definitive analytical machine is the DiamondView produce by the DTC and supplied marketed by the GIA. All of the major diamond testing laboratories world wide are required to have these machines.


See also

A number of large or extraordinarily colored diamonds have gained fame, both as exquisite examples of the beautiful nature of diamonds, and because of the famous people who wore, bought, and sold them. ... One unit cell of the diamond cubic crystal structure. ...

References

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  3. ^ Pliny the Elder. Natural History: A Selection. Penguin Classics, p. 371. ISBN 0140444130. 
  4. ^ "Chinese made first use of diamond", BBC News, 17 May 2005. Retrieved on 2007-03-21. 
  5. ^ http://invsee.asu.edu/nmodules/Carbonmod/point.html
  6. ^ a b c d e f g h i j k l American Museum of Natural History. "The Nature of Diamonds" Retrieved March 9, 2005
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  8. ^ Field, J E (1981). "Strength and Fracture Properties of Diamond". Philosophical Magazine A 43 (3): 595–618. Taylor and Francis Ltd. Retrieved on 2006-02-11. 
  9. ^ Rare blue diamond breaks world record in HK sale, YAHOO! News
  10. ^ Science Experiment22
  11. ^ a b c d e Diamonds and Diamond Grading: Lesson 4 How Diamonds Form. Gemological Institute of America,, Carlsbad, California., 2002
  12. ^ M. Sevdermish and A. Mashiah (1995). The Dealer's Book of Gems and Diamonds. Kal Printing House, Israel. 
  13. ^ Webster, Robert, and Read, Peter G. (Ed.) (2000). Gems: Their sources, descriptions and identification (5th ed.), p. 17. Butterworth-Heinemann, Great Britain. ISBN 0-7506-1674-1.
  14. ^ Garai, J.; Haggerty, S.E.; Rekhi, S.; Chance, M. (2006). "Infrared Absorption Investigations Confirm the Extraterrestrial Origin of Carbonado Diamonds". The Astrophysical Journal 653 (2): L153-L156. doi:10.1086/510451. 
  15. ^ Diamonds from Outer Space: Geologists Discover Origin of Earth's Mysterious Black Diamonds. National Science Foundation (8 January 2007). Retrieved on 2007-10-28.
  16. ^ a b c Hershey MS PhD, Willard (1940). The Book of Diamonds. Hearthside Press New York. 
  17. ^ Catelle, W.R. (1911). The Diamond. John Lane Company.  Page 159 discussion on Alluvial diamonds in India and elsewhere as well as earliest finds
  18. ^ Ball, V (1881). Diamonds, Gold and Coal of India. London, Truebner & Co..  Ball was a Geologist in British service. Chapter I, Page 1
  19. ^ a b Janse, A J A. "Global Rough Diamond Production Since 1870". Gems and Gemology XLIII (Summer 2007): 98-119. GIA date=2007. Retrieved on 2007-09-10. 
  20. ^ a b Lorenz, V (2007). "Argyle in Western Australia: The world's richest diamondiferous pipe; its past and future". Gemmologie, Zeitschrift der Deutschen Gemmologischen Gesellschaft 56 (1/2): 35-40. DGemG. 
  21. ^ Marshall, Stephen; Josh Shore (2004). The Diamond Life. Retrieved on 2007-03-21.
  22. ^ Joint Resolution - World Federation of Diamond Bourses (WFDB) and International Diamond Manufacturers Association. World Diamond Council (July 19, 2000). Retrieved on 2006-11-05.
  23. ^ Zoellner, Tom (2006). The Heartless Stone: A Journey Through the World of Diamonds, Deceit, and Desire. St. Martin's Press. ISBN 0312339690. 
  24. ^ Bourse listing. World Federation of Diamond Bourses. Retrieved on 2007-04-04.
  25. ^ The Nature of Diamonds: 5. Growing Diamonds. American Museum of Natural History. Retrieved on 2007-03-21.
  26. ^ Shigley et al., J E (2002). "Gemesis Laboratory Created Diamonds". Gems and Gemology 38 (4): 301–309. GIA. Retrieved on 2007-05-28. 
  27. ^ Shigley et al., J E (2004). "Lab Grown Colored Diamonds from Chatham Created Gems". Gems and Gemology 40 (2): 128-145. GIA. Retrieved on 2007-05-28. 
  28. ^ O'Donoghue, Michael (2006). Gems. Elsevier.  Page 101, 102
  29. ^ ESSEF Swiss Gemmological Institute
  30. ^ Welbourn, Christopher (2006). "Identification of Synthetic Diamonds: Present Status and Future Developments/Proceedings of the 4th International Gemological Symposium". Gems and Gemology 42 (3): 34-35. GIA. Retrieved on 2007-05-28. 
  31. ^ Shigley, J E (Juni 2007). "Observations on new coated gemstones". Gemmologie: Zeitschrift der Deutschen Gemmologischen Gesellschaft 56 (1/2): 53-56. DGemG. Retrieved on 2007-08-07. 

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Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... May 28 is the 148th day of the year (149th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 219th day of the year (220th in leap years) in the Gregorian calendar. ... is the 73rd day of the year (74th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 73rd day of the year (74th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... March 10 is the 69th day of the year (70th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 80th day of the year (81st in leap years) in the Gregorian calendar. ... Year 2001 (MMI) was a common year starting on Monday (link displays the 2001 Gregorian calendar). ... March 10 is the 69th day of the year (70th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 33rd day of the year in the Gregorian calendar. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... Chemistry & Engineering News is a weekly chemistry trade magazine published by the American Chemical Society. ... is the 294th day of the year (295th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 305th day of the year (306th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... is the 323rd day of the year (324th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...

External links

Gemology and Jewelry Portal
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Look up Diamond in
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Image File history File links No higher resolution available. ... Image File history File links Commons-logo. ... Wikipedia does not have an article with this exact name. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 150 languages. ... For the CSI episode of the same name, see Precious Metal (CSI episode). ... GOLD refers to one of the following: GOLD (IEEE) is an IEEE program designed to garner more student members at the university level (Graduates of the Last Decade). ... This article is about the chemical element. ... Sterling silver is an alloy of silver containing 92. ... General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ... For other uses, see Palladium (disambiguation). ... For other uses, see Gemstone (disambiguation). ... This article does not cite any references or sources. ... This article or section does not cite its references or sources. ... For other uses, see Sapphire (disambiguation). ... For other uses, see Amethyst (disambiguation). ... For other uses, see Opal (disambiguation). ... Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. ... This article is about the mineral. ... Tanzanite is the blue/purple variety of the mineral zoisite discovered in the Meralani Hills of northern Tanzania in 1967, near the city of Arusha. ... The mineral or gemstone chrysoberyl, not to be confused with beryl, is an aluminate of beryllium with the formula BeAl2O4. ... For other uses, see Amber (disambiguation). ... For other uses, see Pearl (disambiguation). ... For other uses, see Gemstone (disambiguation). ... For other uses, see Crystal (disambiguation). ... This article is about the mineral. ... This article or section does not cite its references or sources. ... Garnet is a group of minerals that have been used since the Bronze Age as gemstones and abrasives. ... Polished jasper pebble, one inch (2. ... A block of lapis lazuli Lapis lazuli is one of the oldest of all gems, with a history of use stretching back 7,000 years. ... For other uses, see Pearl (disambiguation). ... This article is about the mineral. ... This article does not cite any references or sources. ... Sunstone, a feldspar exhibiting in certain directions a brilliant spangled appearance, which has led to its use as an ornamental stone. ... Polished tigers eye gemstone Tigers eye (also Tigers eye, Tiger eye) is a chatoyant gemstone that is usually yellow- to red-brown, with a silky luster. ... For other uses, see Agate (disambiguation). ... For other uses, see Amethyst (disambiguation). ... Chalcedony knife, AD 1000-1200 Bloodstone redirects here. ... The mineral pyrite, or iron pyrite, is iron sulfide, FeS2. ... For other uses, see Quartz (disambiguation). ... Rhodochrosite from Sweet Home Mine, Alma, Colorado, USA Pink is the most common color of Rhodochrosite. ... For other uses, see Sapphire (disambiguation). ... Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. ... The tourmaline mineral group is chemically one of the most complicated groups of silicate minerals. ...


  Results from FactBites:
 
Diamond Jewelry - Diamond Engagement Rings - Learn About Diamonds (352 words)
Four important factors that control a diamond's appearance and durability are often lumped together and called the Four Cs: diamond color, clarity, cut and carat weight.
There are several ways to make a diamond appear larger than it actually is. A diamond's appearance can be enhanced by your choice of cut, shape, and setting.
Created diamonds are becoming more common, but the stones produced by LifeGem are unique.
Diamonds | American Museum of Natural History (156 words)
Diamond is something superb, the peerless "king of gems" that glitters, dazzles, and symbolizes purity and strength.
Diamond is for engagement and the 75th wedding anniversary, for a commitment to never-ending love.
Diamond is exotic, formed in Earth's interior and shot to the surface by extraordinary volcanoes.
  More results at FactBites »

 
 

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