Diamond In mineralogy, diamond (from the ancient Greek ad?µa? – adámas "unbreakable") is an 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 conversion rate from diamond to graphite is negligible at ambient conditions. Diamond is renowned as a material with superlative physical qualities, most of which originate from the strong covalent bonding between its atoms. In particular, diamond has the highest hardness and thermal conductivity of any bulk material. Those properties determine the major industrial application of diamond in cutting and polishing tools. Diamond has remarkable optical characteristics. Because of its extremely rigid lattice, it can be contaminated by very few types of impurities, such as boron and nitrogen. Combined with wide transparency, this results in the clear, colorless appearance of most natural diamonds. Small amounts of defects or impurities (about one per million of lattice atoms) color diamond blue (boron), yellow (nitrogen), brown (lattice defects), green, purple, pink, orange or red. Diamond also has relatively high optical dispersion, that is ability to disperse light of different colors, which results in its characteristic luster. Excellent optical and mechanical properties, combined with efficient marketing, make diamond the most popular gemstone. Most natural diamonds are formed at high-pressure high-temperature conditions existing at depths of 140 to 190 kilometers (87 to 120 mi) in the Earth mantle. Carbon-containing minerals provide the carbon source, and the growth occurs over periods from 1 billion to 3.3 billion years (25% to 75% of the age of the Earth). Diamonds are brought close to the Earth surface through deep volcanic eruptions by a magma, which cools into igneous rocks known as kimberlites and lamproites. Diamonds can also be produced synthetically in a high-pressure high-temperature process which approximately simulates the conditions in the Earth mantle. An alternative, and completely different growth technique is chemical vapor deposition (CVD). 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 been specially developed to distinguish natural and synthetic diamonds and diamond simulants. History See also: Diamond (gemstone) The name diamond is derived from the ancient Greek ad?µa? (adámas), "proper", "unalterable", "unbreakable, untamed", from ?- (a-), "un-" + daµ?? (damáo), "I overpower, I tame".[3] Diamonds are thought to have been first recognized and mined in India, where significant alluvial deposits of the stone could be found many centuries ago along the rivers Penner, Krishna and Godavari. Diamonds have been known in India for at least 3,000 years but most likely 6,000 years.[4] Diamonds have been treasured as gemstones since their use as religious icons in ancient India. Their usage in engraving tools also dates to early human history.[5][6] The 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.[7] In 1772, Antoine Lavoisier used a lens to concentrate the rays of the sun on a diamond in an atmosphere of oxygen, and showed that the only product of the combustion was carbon dioxide, proving that diamond is composed of carbon. Later in 1797, Smithson Tennant repeated and expanded that experiment. By demonstrating that burning diamond and graphite (charcoal) releases the same amount of gas he established the chemical equivalence of these substances.[8] The most familiar use of diamonds today is as gemstones used for adornment, a use which dates back into antiquity. The dispersion of white light into spectral colors is the primary gemological characteristic of gem diamonds. In the 20th century, experts in 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.[9] A large, flawless diamond is known as a paragon. Material properties Main articles: Material properties of diamond and Crystallographic defects in diamond Theoretically predicted phase diagram of carbon Diamond and graphite are two allotropes of carbon: pure forms of the same element that differ in structure. A diamond is a transparent crystal of tetrahedrally bonded carbon atoms (sp3) that crystallizes into the diamond lattice which is a variation of the face centered cubic structure. Diamonds have been adapted for many uses because of the material's exceptional physical characteristics. Most notable are its extreme hardness and thermal conductivity (900–2,320 W•m-1•K-1),[10] as well as wide bandgap and high optical dispersion.[11] Above 1,700 °C (1,973 K / 3,583 °F) in vacuum or oxygen-free atmosphere, diamond converts to graphite; in air, transformation starts at ~700 °C.[12] Naturally occurring diamonds have a density ranging from 3.15–3.53 g/cm3, with pure diamond close to 3.52 g/cm3.[1] Despite the hardness of diamonds, the chemical bonds that hold the carbon atoms in diamonds together are weaker than those that hold together the other form of pure carbon, graphite. The difference is that in diamonds, the bonds form an inflexible three-dimensional lattice. In graphite, the atoms are tightly bonded into sheets, which can slide easily over one another.[13] Hardness Diamond is the hardest natural material known, where hardness is defined as resistance to scratching and is graded between 1 (softest) and 10 (hardest) using the Mohs scale of mineral hardness. Diamond has a hardness of 10 (hardest) on this scale.[14] Diamond's hardness has been known since antiquity, and is the source of its name. Diamond hardness depends on its purity, crystalline perfection and orientation: hardness is higher for flawless, pure crystals oriented to the ?111? direction (along the longest diagonal of the cubic diamond lattice).[15] Therefore, whereas it might be possible to scratch some diamonds with other materials, such as boron nitride, the hardest diamonds can only be scratched by other diamonds. In particular, nanocrystalline diamond aggregates were measured to be harder than any large single crystal diamond. Those aggregates are produced by high-pressure high-temperature treatment of graphite or fullerite (C60).[16] The hardness of diamond contributes to its suitability as a gemstone. Because it can only be scratched by other diamonds, it maintains its polish extremely well. Unlike many other gems, it is well-suited to daily wear because of its resistance to scratching—perhaps contributing to its popularity as the preferred gem in engagement or wedding rings, which are often worn every day. The hardest natural diamonds mostly originate from the Copeton and Bingara fields located in the New England area in New South Wales, Australia. These diamonds are generally small, perfect to semiperfect octahedra, and are used to polish other diamonds. Their hardness is associated with the crystal growth form, which is single-stage crystal growth. Most other diamonds show more evidence of multiple growth stages, which produce inclusions, flaws, and defect planes in the crystal lattice, all of which affect their hardness. It is possible to treat regular diamonds under a combination of high pressure and high temperature to produce diamonds that are harder than the diamonds used in hardness gauges.[17] Somewhat related to hardness is another mechanical property toughness, which is a material's ability to resist breakage from forceful impact. The toughness of natural diamond has been measured as 2.0 MPa•m1/2,[18] and the critical stress intensity factor is 3.4 MN•m-3/2.[19] Those values are 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 has a cleavage plane and is therefore more fragile in some orientations than others. Diamond cutters use this attribute to cleave some stones, prior to faceting.[20] 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 diamonds, which are excellent electrical insulators.[21] The conductivity and blue color originate from boron impurity. Boron substitutes for carbon atoms in the diamond lattice, donating a hole into the valence band.[21] Substantial conductivity is commonly observed in nominally undoped diamond grown by chemical vapor deposition. This conductivity is associated with hydrogen-related species adsorbed at the surface, and it can be removed by annealing or other surface treatments.[22][23] Color Main article: Diamond color Brown diamonds at the National Museum of Natural History in Washington, D.C Diamond has a wide bandgap of 5.5 eV corresponding to the deep ultraviolet wavelength of 225 nanometers. This means pure diamond should transmit visible light and appear as a clear colorless crystal. Colors in diamond originate from lattice defects and impurities. The diamond crystal lattice is exceptionally strong and only atoms of nitrogen, boron and hydrogen can be introduced into diamond during the growth at significant concentrations (up to atomic percents). Transition metals Ni and Co, which are commonly used for growth of synthetic diamond by high-pressure high-temperature techniques, have been detected in diamond as individual atoms; the maximum concentration is 0.01% for Ni[24] and even much less for Co. Virtually any element can be introduced to diamond by ion implantation.[25] Nitrogen is by far the most common impurity found in gem diamonds. Nitrogen is responsible for the yellow and brown color in diamonds. Boron is responsible for the gray blue colors.[11] Color in diamond has two additional sources: irradiation (usually by alpha particles), that causes the color in green diamonds; and physical deformation of the diamond crystal known as plastic deformation. Plastic deformation is the cause of color in some brown[26] and perhaps pink and red diamonds.[27] In order of rarity, colorless diamond, by far the most common, is followed by yellow and brown, by far the most common colors, then by blue, green, black, translucent white, pink, violet, orange, purple, and the rarest, red.[20] "Black", or Carbonado, diamonds are not truly black, but rather contain numerous dark inclusions that give the gems their dark appearance. Colored diamonds contain impurities or structural defects that cause 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.[20] 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). Diamonds of a different color, such as blue, are called fancy colored diamonds, and fall under a different grading scale.[20] In 2008, the Wittelsbach Diamond, a 35.56-carat (7.11 g) blue diamond once belonging to the King of Spain, fetched over US$24 million at a Christie's auction.[28] In May 2009, a 7.03-carat (1.41 g) blue diamond fetched the highest price per carat ever paid for a diamond when it was sold at auction for 10.5 million Swiss francs (6.97 million Euro or US$9.5 million at the time).[29] That record was however beaten the same year: a 5-carat vivid pink diamond was sold for $10.8 million in Hong Kong on December 1, 2009.[30] Identification Diamonds can be identified by their high thermal conductivity. Their high refractive index is also indicative, but other materials have similar refractivity. Diamonds cut glass, but this does not positively identify a diamond because other materials, such as quartz, also lie above glass on the Mohs scale and can also cut it. Diamonds can scratch other diamonds, but this can result in damage to one or both stones. Hardness tests are infrequently used in practical gemology because of their potentially destructive nature.[14] The extreme hardness and high value of diamond means that gems are typically polished slowly using painstaking traditional techniques and greater attention to detail than is the case with most other gemstones;[8] these tend to result in extremely flat, highly polished facets with exceptionally sharp facet edges. Diamonds also possess an extremely high refractive index and fairly high dispersion. Taken together, these factors affect the overall appearance of a polished diamond and most diamantaires still rely upon skilled use of a loupe (magnifying glass) to identify diamonds 'by eye'.[31] Natural history The formation of natural diamond requires very specific conditions—exposure of carbon-bearing materials to high pressure, ranging approximately between 45 and 60 kilobars (4.5 and 6 GPa), but at a comparatively low temperature range between approximately 900–1300 °C. 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.[32] Formation in cratons One face of an uncut octahedral diamond, showing trigons (of positive and negative relief) formed by natural chemical etching The conditions for diamond formation to happen in the lithospheric mantle occur at considerable depth corresponding to the requirements of temperature and pressure. These depths are estimated between 140 and 190 km though occasionally diamonds have crystallized at depths about 300 km as well.[33] 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. 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. Long residence in the cratonic lithosphere allows diamond crystals to grow larger.[33] 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. These two different source of carbon have measurably different 13C:12C ratios. Diamonds that have come to the Earth's surface are generally quite old, ranging from under 1 billion to 3.3 billion years old. This is 22% to 73% of the age of the Earth.[33] Diamonds occur most often as euhedral or rounded octahedra and twinned octahedra known as macles. As diamond's crystal structure has a cubic arrangement of 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 at the surfaces of the octahedron. These different shapes and habits of some diamonds result from differing external circumstances. Diamonds (especially those with rounded crystal faces) are commonly found coated in nyf, an opaque gum-like skin.[34] Formation in meteorite impact craters Diamonds can also form under other naturally occurring high-pressure conditions. Very small diamonds of micrometer and nanometer sizes, known as microdiamonds or nanodiamonds respectively, 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 an indicator of ancient impact craters.[32] Extraterrestrial formation Not all diamonds found on Earth originated here. A type of diamond called carbonado that is found in South America and Africa may have been deposited there via an asteroid impact (not formed from the impact) about 3 billion years ago. These diamonds may have formed in the intrastellar environment, but as of 2008, there was no scientific consensus on how carbonado diamonds originated.[35][36] Presolar grains in many meteorites found on Earth contain nanodiamonds of extraterrestrial origin, probably formed in supernovas. Scientific evidence indicates that white dwarf stars have a core of crystallized carbon and oxygen nuclei. The largest of these found in the universe so far, BPM 37093, is located 50 light-years (4.7×1014 km) away in the constellation Centaurus. A news release from the Harvard-Smithsonian Center for Astrophysics described the 2,500-mile (4,000 km)-wide stellar core as a diamond.[37] It was referred to as Lucy, after the Beatles' song "Lucy in the Sky With Diamonds".[17][38] Surfacing 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[33]—150 km (93 mi) 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.[33] 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 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.[33] The magma in volcanic pipes is usually one of two characteristic types, which cool into igneous rock known as either kimberlite or lamproite.[33] 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[33] which are often altered to serpentine by heat and fluids during and after eruption. Certain indicator minerals typically occur within diamantiferous kimberlites and are used as mineralogical 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 chromium garnets (usually bright red chromium-pyrope, and occasionally green ugrandite-series garnets), eclogitic garnets, orange titanium-pyrope, red high-chromium spinels, dark chromite, bright green chromium-diopside, glassy green olivine, black picroilmenite, and magnetite. 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.[33] 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 have been eroded out of their kimberlite or lamproite matrix, and accumulated 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 size and density. Diamonds have also rarely been found in deposits left behind by glaciers (notably in Wisconsin and Indiana); in contrast to alluvial deposits, glacial deposits are minor and are therefore not viable commercial sources of diamond.[33] Production Diamond output in 2005 See also: List of diamond mines Approximately 130 million carats (26,000 kg (57,000 lb)) of diamonds are mined annually, with a total value of nearly US$9 billion, and about 100,000 kg (220,000 lb) are synthesized annually.[39] 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.[40] They are mined from kimberlite and lamproite volcanic pipes, which can bring diamond crystals, originating from deep within the Earth where high pressures and temperatures enable them to form, to the surface. The mining and distribution of natural diamonds are subjects of frequent controversy such as concerns over the sale of blood diamonds or conflict diamonds by African paramilitary groups.[41] 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 (see figure). Only a very small fraction of the diamond ore consists of actual diamonds. The ore is crushed, during which care is required not to destroy larger diamonds, and then 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,[42] the separation was done with grease belts; diamonds have a stronger tendency to stick to grease than the other minerals in the ore.[20] Historically diamonds were found only in alluvial deposits in southern India.[43] India led the world in diamond production from the time of their discovery in approximately the 9th century BC[4][44] 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 were found in 1725.[4] Diamond extraction from primary deposits (kimberlites and lamproites) started in the 1870s after the discovery of the Diamond Fields in South Africa.[45] Production has increased over time and now an accumulated total of 4.5 billion carats have been mined since that date.[46] Twenty percent of that amount has been mined in the last five years, and during the last 10 years, nine new mines have started production; four more are waiting to be opened soon. Most of these mines are located in Canada, Zimbabwe, Angola, and one in Russia.[46] In the U.S., diamonds have been found in Arkansas, Colorado, and Montana.[47][48] In 2004, the discovery of a microscopic diamond in the U.S. led to the January 2008 bulk-sampling of kimberlite pipes in a remote part of Montana.[48] Today, most commercially viable diamond deposits are in Russia (mostly in Sakha Republic, for example Mir pipe and Udachnaya pipe), Botswana, Australia (Northern and Western Australia) and the Democratic Republic of Congo.[49] In 2005, Russia produced almost one-fifth of the global diamond output, reports the British Geological Survey. Australia boasts the richest diamantiferous pipe, with production from the Argyle diamond mine reaching peak levels of 42 metric tons per year in the 1990s.[47][50] There are also commercial deposits being actively mined in the Northwest Territories of Canada and Brazil.[40] Diamond prospectors continue to search the globe for diamond-bearing kimberlite and lamproite pipes. Controversial sources Main articles: Kimberley Process, Blood diamond, and Child labour in the diamond industry 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.[41] Major diamond trading corporations continue to fund and fuel these conflicts by doing business with armed groups. In response to public concerns that their diamond purchases were contributing to war and human rights abuses in central and western Africa, the United Nations, the diamond industry and diamond-trading nations introduced the Kimberley Process in 2002.[51] The Kimberley Process aims to ensure that conflict diamonds do not become intermixed with the diamonds not controlled by such rebel groups. This is done by requiring diamond-producing countries to provide proof that the money they make from selling the diamonds is not 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, some still find their way in. Conflict diamonds constitute 2–3% of all diamonds traded.[52] Two major flaws still hinder the effectiveness of the Kimberley Process: (1) the relative ease of smuggling diamonds across African borders, and (2) the violent nature of diamond mining in nations that are not in a technical state of war and whose diamonds are therefore considered "clean".[51] The Canadian Government has set up a body known as Canadian Diamond Code of Conduct[53] to help authenticate Canadian diamonds. This is a stringent tracking system of diamonds and helps protect the "conflict free" label of Canadian diamonds.[54] Commercial markets See also: Diamonds as an investment A round brilliant cut diamond set in a ring The diamond industry can be separated into two 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. Gemstones and their distribution Main article: Diamond (gemstone) A large trade in gem-grade diamonds exists. Unlike other commodities, such as most precious metals, there is a substantial mark-up in the retail sale of gem diamonds.[55] There is a well-established market for resale of polished diamonds (e.g. pawnbroking, auctions, second-hand jewelry stores, diamantaires, bourses, etc.). One hallmark of the trade in gem-quality diamonds is its remarkable concentration: wholesale trade and diamond cutting is limited to just a few locations; In 2003, 92% of the world's diamonds were cut and polished in Surat, India.[56] Other important centers of diamond cutting and trading are Antwerp, where the International Gemological Institute is based, London, New York City, Tel Aviv, and Amsterdam. A single company—De Beers—controls a significant proportion of the trade in diamonds.[57] They are based in Johannesburg, South Africa and London, England. One contributory factor is the geological nature of diamond deposits: several large primary kimberlite-pipe mines each account for significant portions of market share (such as the Jwaneng mine in Botswana, which is a single large pit operated by De Beers that can produce between 12.5 to 15 million carats of diamonds per year,[58]) whereas secondary alluvial diamond deposits tend to be fragmented amongst many different operators because they can be dispersed over many hundreds of square kilometers (e.g., alluvial deposits in Brazil). 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.[59] This makes Antwerp a de facto "world diamond capital". Another important diamond center is New York City, where almost 80% of the world's diamonds are sold, including auction sales.[59] The DeBeers company, as the world's largest diamond miner holds a 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 Diamond Trading Company (DTC) is a subsidiary of De Beers and markets rough diamonds from De Beers-operated mines. De Beers and its subsidiaries own mines that produce some 40% of annual world diamond production. For most of the 20th century over 80% of the world's rough diamonds passed through De Beers,[60] but in the period 2001–2009 the figure has decreased to around 45%.[61] De Beers sold off the vast majority of its diamond stockpile in the late 1990s – early 2000s[62] and the remainder largely represents working stock (diamonds that are being sorted before sale).[63] This was well documented in the press[64] but remains little known to the general public. As a part of reducing its influence, De Beers withdrew from purchasing diamonds on the open market in 1999 and ceased, at the end of 2008, purchasing Russian diamonds mined by the largest Russian diamond company Alrosa.[65] Alrosa had to suspend their sales in October 2008 due to the global energy crisis and was expected to resume them in late 2009.[66] Apart from Alrosa, other important diamond mining companies include BHP Billiton, which is the world's largest mining company;[67] Rio Tinto Group, the owner of Argyle (100%), Diavik (60%), and Murowa (78%) diamond mines;[68] and Petra Diamonds, the owner of several major diamond mines in Africa. 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 centers such as Tel Aviv, Antwerp, Johannesburg and other cities across the USA, Europe and Asia.[20] 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. WFDB's additional activities include sponsoring the World Diamond Congress every two years, as well as the establishment of the International Diamond Council (IDC) to oversee diamond grading. Once purchased by Sightholders (which is a trademark term referring to the companies that have a three-year supply contract with DTC), diamonds are cut and polished in preparation for sale as gemstones ('industrial' stones are regarded as a by-product of the gemstone market; they are used for abrasives).[69] The cutting and polishing of rough diamonds is a specialized skill that is concentrated in a limited number of locations worldwide.[69] Traditional diamond cutting centers are Antwerp, Amsterdam, Johannesburg, New York City, and Tel Aviv. Recently, diamond cutting centers have been established in China, India, Thailand, Namibia and Botswana.[69] 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.[59] Diamonds which have been prepared as gemstones are sold on diamond exchanges called bourses. There are 26 registered diamond bourses in the world.[70] Bourses are 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 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 US$57 billion in retail sales.[71] Marketing The image of diamond as a valuable commodity has been preserved through clever marketing campaigns. In particular, 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".[7] It should be noted however, that graphite is the most stable allotrope of carbon, and as such diamond should in theory eventually become graphite. Another example of successful diamond marketing is brown Australian diamonds. Brown-colored diamonds have always constituted a significant part of the diamond production, but were considered worthless for jewelry; they were not even assessed on the diamond color scale, and were predominantly used for industrial purposes. The attitude has changed drastically after the development of Argyle diamond mine in Australia in 1986. As a result of an aggressive marketing campaign, brown diamonds have become acceptable gems.[72][73] The change was mostly due to the numbers: the Argyle mine, with its 35 million carats (7,000 kg) of diamonds per year, makes about one-third of global production of natural diamonds;[74] 80% of Argyle diamonds are brown.[75] Cutting Main articles: Diamond cutting and Diamond cut The Darya-I-Nur Diamond—an example of unusual diamond cut and jewelry arrangement The mined rough diamonds are converted into gems through a multi-step process called "cutting". Diamonds are extremely hard, but also brittle and can be split up by a single blow. Therefore, diamond cutting is traditionally considered as a delicate procedure requiring skills, scientific knowledge, tools and experience. Its final goal is to produce a faceted jewel where the specific angles between the facets would optimize the diamond luster, that is dispersion of white light, whereas the number and area of facets would determine the weight of the final product. The weight reduction upon cutting is significant and can be of the order of 50%.[42] Several possible shapes are considered, but the final decision is often determined not only by scientific, but also practical considerations. For example the diamond might be intended for display or for wear, in a ring or a necklace, singled or surrounded by other gems of certain color and shape.[76] The most time-consuming part of the cutting is the preliminary analysis of the rough stone. It needs to address a large number of issues, bears much responsibility, and therefore can last years in case of unique diamonds. The following issues are considered: • The hardness of diamond and its ability to cleave strongly depend on the crystal orientation. Therefore, the crystallographic structure of the diamond to be cut is analyzed using X-ray diffraction in order to choose the optimal cutting directions. • Most diamonds contain visible non-diamond inclusions and crystal flaws. The cutter has to decide which flaws are to be removed by the cutting and which could be kept. • The diamond can be split by a single, well calculated blow of a hammer to a pointed tool, which is quick, but risky. Alternatively, it can be cut with a diamond saw, which is a more reliable but tedious procedure.[76][77] After initial cutting, the diamond is shaped in numerous stages of polishing. Unlike cutting, which is a responsible but quick operation, polishing removes material by gradual erosion and is extremely time consuming. The associated technique is well developed; it is considered as a routine and can be performed by technicians.[78] After polishing, the diamond is reexamined for possible flaws, either remaining or induced by the process. Those flaws are concealed through various diamond enhancement techniques, such as repolishing, crack filling, or clever arrangement of the stone in the jewelry. Remaining non-diamond inclusions are removed through laser drilling and filling of the voids produced.[14] Industrial uses A scalpel with synthetic diamond blade Close-up photograph of an angle grinder blade with tiny diamonds shown embedded in the metal 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 diamonds, such as clarity and color, irrelevant for most applications. This helps explain why 80% of mined diamonds (equal to about 135 million carats or 27 metric tons annually), unsuitable for use as gemstones, are destined for industrial use. In addition to mined diamonds, synthetic diamonds found industrial applications almost immediately after their invention in the 1950s; another 570 million carats (114 tons) of synthetic diamond is produced annually for industrial use. Approximately 90% of diamond grinding grit is currently of synthetic origin.[40] The boundary between gem-quality diamonds and industrial diamonds is poorly defined and partly depends on market conditions (for example, if demand for polished diamonds is high, some suitable stones will be polished into low-quality or small gemstones rather than being sold for industrial use). Within the category of industrial diamonds, there is a sub-category comprising the lowest-quality, mostly opaque stones, which are known as bort.[79] 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. Common industrial adaptations of this ability include diamond-tipped drill bits and saws, and the use of diamond powder as an abrasive. Less expensive industrial-grade diamonds, known as bort, with more flaws and poorer color than gems, are used for such purposes.[80] Diamond is not suitable for machining ferrous alloys at high speeds, as carbon is soluble in iron at the high temperatures created by high-speed machining, leading to greatly increased wear on diamond tools compared to alternatives.[81] Specialized applications include use in laboratories as containment for high pressure experiments (see diamond anvil cell), high-performance bearings, and limited use in specialized windows.[79] With the continuing advances being made in the production of synthetic diamonds, future applications are becoming feasible. Garnering much excitement is the possible use of diamond as a semiconductor suitable to build microchips, or the use of diamond as a heat sink[82] in electronics. Synthetics, simulants, and enhancements Synthetics Main article: Synthetic diamond Synthetic diamonds of various colors grown by the high-pressure high-temperature technique Synthetic diamonds are diamonds manufactured in a laboratory, as opposed to natural diamonds which form naturally within the Earth. The gemological and industrial uses of diamond have created a large demand for rough stones. This demand has 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.[33] The majority of commercially available synthetic diamonds are yellow and are produced by so called High Pressure High Temperature (HPHT) processes.[83] 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 synthesis.[84] Colorless gem cut from diamond grown by chemical vapor deposition Another popular method of growing synthetic diamond is chemical vapor deposition (CVD). The growth occurs under low pressure (below atmospheric pressure). It involves feeding a mixture of gases (typically 1 to 99 methane to hydrogen) into a chamber and splitting them to chemically active radicals in a plasma ignited by microwaves, hot filament, arc discharge, welding torch or laser.[85] This method is mostly used for coatings, but can also produce single crystals several millimeters in size (see picture).[39] 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. Despite this fact, a purchaser is more likely to encounter a synthetic when looking for a fancy-colored diamond because nearly all synthetic diamonds are fancy-colored, while only 0.01% of natural diamonds are.[86] Simulants Main article: Diamond simulant Gem-cut synthetic silicon carbide 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. The most familiar diamond simulant to most consumers is cubic zirconia. The popular gemstone moissanite (silicon carbide) is often treated as a diamond simulant, although it is a gemstone in its own right. While moissanite looks similar to diamond, its main disadvantage as a diamond simulant is that cubic zirconia is far cheaper and arguably equally convincing. Both cubic zirconia and moissanite are produced synthetically.[87] Enhancements Main article: Diamond enhancement Diamond enhancements are specific treatments performed on natural or synthetic 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.[88] Coatings are increasingly used to give a diamond simulant such as cubic zirconia a more "diamond-like" appearance. One such substance is diamond-like carbon—an amorphous carbonaceous material that has some physical properties similar to those of the diamond. Advertising suggests that such a coating would transfer some of these diamond-like properties to the coated stone, hence enhancing the diamond simulant. Techniques such as Raman spectroscopy should easily identify such a treatment.[89] Identification Early diamond identification tests included a scratch test relying on the superior hardness of diamond. This test is destructive, as a diamond can scratch diamond, and is rarely used nowadays. Instead, diamond identification relies on its superior thermal conductivity. Electronic thermal probes are widely used in the gemological centers to separate diamonds from their imitations. These probes consist of a pair of battery-powered thermistors mounted in a fine copper tip. One thermistor functions as a heating device while the other measures the temperature of the copper tip: if the stone being tested is a diamond, it will conduct the tip's thermal energy rapidly enough to produce a measurable temperature drop. This test takes about 2–3 seconds.[90] Whereas the thermal probe can separate diamonds from most of their simulants, distinguishing between various types of diamond, for example synthetic or natural, irradiated or non-irradiated, etc., requires more advanced, optical techniques. Those techniques are also used for some diamonds simulants, such as silicon carbide, which pass the thermal conductivity test. Optical techniques can distinguish between natural diamonds and synthetic diamonds. They can also identify the vast majority of treated natural diamonds.[91] "Perfect" crystals (at the atomic lattice level) have never been found, so both natural and synthetic diamonds always possess characteristic imperfections, arising from the circumstances of their crystal growth, that allow them to be distinguished from each other.[92] Laboratories use techniques such as spectroscopy, microscopy and luminescence under shortwave ultraviolet light to determine a diamond's origin.[91] They also use specially made machines to aid them in the identification process. Two screening machines are the DiamondSure and the DiamondView, both produced by the DTC and marketed by the GIA.[93] Several methods for identifying synthetic diamonds can be performed, depending on the method of production and the color of the diamond. CVD diamonds can usually be identified by an orange fluorescence. D-J colored diamonds can be screened through the Swiss Gemmological Institute's[94] Diamond Spotter. Stones in the D-Z color range can be examined through the DiamondSure UV/visible spectrometer, a tool developed by De Beers.[92] Similarly, natural diamonds usually have minor imperfections and flaws, such as inclusions of foreign material, that are not seen in synthetic diamonds.

The government is going to formulate a policy to cut down the amount of sulphur in diesel fuel to 50 parts per million to ensure sustainable environment by reducing vehicular air pollution and encouraging adoption of cleaner vehicle technologies.
A project called ‘air quality improvement through clean fuels and vehicles’ has already been taken to this end, said a senior Department of Environment official.
The environment and forest ministry with the United Nations Environment Programme has undertaken the project which the environment department will implement.
The UNEP is helping Bangladesh to implement the project as part of its programme called ‘Partnership for Clean Fuels and Vehicles’ aimed at reducing vehicular air pollution in developing countries by promoting elimination of lead and reduction of sulphur in petroleum fuels.
‘Departmental special project evaluation committee of the environment and forest ministry has already approved the project,’ deputy director (planning and development) of the environment department Quazi Sarwar Imtiaz Hashmi told New Age.
He said the project director was yet to be appointed as the project was yet to get the go-ahead. The project was scheduled to begin in November.
The project involving Tk 41.93 lakh is scheduled to be completed by December 2010; Tk 25.53 of the project fund will come in grant from the UNEP and the remaining amount of the fund will be provided by the Bangladesh government.
The project will work out how prevalence of sulphur in diesel fuel can be reduced to 50ppm and how vehicular emissions can be reduced by adopting cleaner vehicle technologies.
Under the project, a sensitisation programme at the national level on the importance of sulphur reduction in diesel and use of cleaner vehicles will also be taken.
According to the Bangladesh Petroleum Corporation, imported diesel contains 2500ppm of sulphur while refined diesel contains 9000ppm of sulphur which has an immediate effect on the health of the people.
The UNEP in its Forth Global Partnership Meeting for Clean Fuels and Vehicles in Nairobi in 2006 decided it would work with others with a goal of reducing sulphur in fuels globally to less than 50ppm.
This initiative has 85 partners from governments, private sector and non-governmental and international organisations.

From Wikipedia, the free encyclopedia SMS Moltke[Note 1] was the lead ship of the Moltke-class battlecruisers of the German Imperial Navy, named after the 19th century German field marshal Helmuth von Moltke. Commissioned on 30 September 1911, the ship was the second battlecruiser commissioned into the Imperial Navy. Moltke, along with her sister ship Goeben, was an enlarged version of the previous German battlecruiser design, Von der Tann. The ship was very similar to Von der Tann, but had increased armor protection and two more main guns in an additional turret. Compared to her British rivals—the Indefatigable class—Moltke and her sister Goeben were significantly larger and better armored.[Note 2] The ship participated in most of the major fleet actions conducted by the German Navy during the First World War, including the Battles of Dogger Bank and Jutland in the North Sea, and the Battle of the Gulf of Riga and Operation Albion in the Baltic. Moltke was damaged several times during the war: the ship was hit by heavy caliber gunfire at Jutland, and torpedoed twice by British submarines while on fleet advances. Following the end of the war in 1918, Moltke, along with most of the High Seas Fleet, was interned at Scapa Flow pending a decision by the Allies as to the fate of the fleet. The ship met her end when she was scuttled, along with the rest of the High Seas Fleet, in 1919 to prevent them from falling into British hands. The wreck of Moltke was raised in 1927 and scrapped at Rosyth from 1927 to 1929. Development In a conference in May 1907, the Germany Navy Office decided to follow up the unique[Note 3] Von der Tann battlecruiser with an enlarged design.[4] 44 million marks were allocated for the 1908 fiscal year, which created the possibility of increasing the main guns to 30.5 cm (12 in) in diameter, instead of the 28 cm (11 in) weapons on the preceding design. However, Admiral Alfred von Tirpitz, along with the Construction Department, argued that increasing the number of guns from 8 to 10 would be preferable instead of increasing the size of the previous battery.[4] The General Navy Department held that for the new design to fight in the battle line, 30.5 cm (12 in) guns were necessary. Ultimately, Tirpitz and the Construction Department won the debate, and Moltke was equipped with ten 28 cm (11 in) guns. It was also mandated by the Construction Department that armor protection was to be at least as good as that of Von der Tann. The ship was also to have a top speed of at least 24.5 knots (45.4 km/h).[4] During the design process, the ship's weight continued to grow due to the increase in the size of the citadel, armor thickness, the additions to the ammunition stores, and the rearrangement of the boiler system.[4] The naval arms race between Germany and Britain put a great deal of stress on the Navy design staff, and prompted the decision to build two ships of the new design. They were assigned under the contract names of "Cruiser G" and "Cruiser H." Blohm & Voss received both contracts in 1908; "Cruiser G" was assigned to the 1908–1909 building year, while "Cruiser H" was assigned to 1909–1910.[5] The contract for "Cruiser G" was awarded on 17 September 1908, under building number 200. The keel was laid on 7 December 1908, and the ship was launched on 7 April 1910. "Cruiser G" was commissioned on 30 September 1911, as SMS Moltke.[1] Service record Pre-war At the launching of the ship on 7 April 1910, Helmuth von Moltke the Younger christened the ship after his uncle Helmuth von Moltke the Elder,[6] the Chief of Staff of the Prussian Army in the mid 19th century.[2] On 11 September 1911, a crew composed of dockyard workers transferred the ship from Hamburg to Kiel through the Skagen.[7] On 30 September, the ship was commissioned, under the command of Kapitän zur See von Mann,[2] and replaced Roon in the Reconnaissance Unit. Sea trials continued until 1 April 1912.[7] SMS Moltke in New York in 1912. She was the first and only German capital ship to ever visit the United States. On 11 May 1912 she left Kiel, accompanied by the light cruisers Stettin and Bremen, and arrived off Hampton Roads, Virginia, on 30 May 1912. After touring the East Coast for two weeks, she returned to Kiel on 24 June.[7] In July 1912, Moltke escorted Kaiser Wilhelm II's yacht to Russia. Upon returning, Moltke's commander was replaced by KzS Magnus von Levetzow,[2] and the ship became the Reconnaissance Force flagship until 23 June 1914, when the commander's flag was transferred to the new battlecruiser Seydlitz.[7] There was some consideration given to deploying Moltke to the Far East in order to replace the armored cruiser Scharnhorst, but the plan was abandoned when it became apparent that Goeben needed replacement in the Mediterranean. Moltke was then scheduled to transfer to replace her sister ship, but this plan was interrupted by the outbreak of World War I.[7] World War I As was the case with almost all German capital ships during World War I, Moltke's action was somewhat limited. However, she did participate in most of the major fleet actions conducted by the High Seas Fleet. At the start of the war, the ship was assigned to the I Scouting Group of the High Seas Fleet, under the command of Rear Admiral Franz Hipper.[7] Battle of Heligoland Bight Main article: Battle of Heligoland Bight Shortly after the outbreak of World War I, on 28 August 1914, Moltke participated in the Battle of Heligoland Bight. During the morning, British cruisers from the Harwich Force attacked the German destroyers patrolling the Heligoland Bight. Six German light cruisers—Köln, Strassburg, Stettin, Frauenlob, Stralsund, and Ariadne—responded to the attack and inflicted serious damage to the British raiders. However, the arrival at approximately 13:37 of the British 1st Battlecruiser Squadron, under the command of Vice Admiral David Beatty, quickly put the German ships at a disadvantage.[8] Along with the rest of the I Scouting Group battlecruisers, Moltke was stationed in the Wilhelmshaven Roads on the morning of the battle. By 08:50, Rear Admiral Hipper had requested permission from Admiral Friedrich von Ingenohl, the commander in chief of the High Seas Fleet, to send Moltke and Von der Tann to relieve the beleaguered German cruisers.[9] Moltke was ready to sail by 12:10, but the low tide prevented the ships from being able to pass over the sand bar at the mouth of the Jade Estuary safely. At 14:10, Moltke and Von der Tann were able to cross the Jade bar; Hipper ordered the German cruisers to fall back to his ships, while Hipper himself was about an hour behind in the battlecruiser Seydlitz. At 14:25, the remaining light cruisers—Strassburg, Stettin, Frauenlob, Stralsund, and Ariadne—rendezvoused with the battlecruisers.[10] Seydlitz arrived on the scene by 15:10, while Ariadne succumbed to battle damage and sank. Hipper ventured forth cautiously to search for the two missing light cruisers, Mainz and Köln, which had already sunk. By 16:00, the German flotilla turned around to return to the Jade Estuary, arriving at approximately 20:23.[11] Bombardment of Yarmouth Main article: Raid on Yarmouth On 2 November 1914, Moltke, Rear Admiral Hipper's flagship Seydlitz, Von der Tann, and Blücher along with four light cruisers left the Jade Estuary and steamed towards the English coast.[12] The flotilla arrived off Great Yarmouth at daybreak the following morning and bombarded the port, while the light cruiser Stralsund laid a minefield. The British submarine D5 responded to the bombardment, but struck one of the mines laid by Stralsund and sank. Shortly thereafter, Hipper ordered his ships to turn back to German waters. However, while Hipper's ships were returning to German waters, a heavy fog covered the Heligoland Bight, so the ships were ordered to halt until visibility improved so they could safely navigate the defensive minefields. The armored cruiser Yorck left the Jade without permission, and while en route to Wilhelmshaven made a navigational error that led the ship into one of the German minefields. Yorck struck two mines and quickly sank; the coastal defense ship Hagen was able to save 127 men of the crew.[12] Bombardment of Scarborough, Hartlepool, and Whitby Main article: Raid on Scarborough, Hartlepool and Whitby It was decided by Admiral von Ingenohl that another raid on the English coast was to be carried out, in the hopes of luring a portion of the Grand Fleet into combat, where it could be destroyed.[12] At 03:20 on 15 December, Moltke, Seydlitz, Von der Tann, Derfflinger, and Blücher, along with the light cruisers Kolberg, Strassburg, Stralsund, and Graudenz, and two squadrons of torpedo boats left the Jade.[13] The ships sailed north past the island of Heligoland, until they reached the Horns Reef lighthouse, at which point the ships turned west towards Scarborough. Twelve hours after Hipper left the Jade, the High Seas Fleet, consisting of 14 dreadnoughts and 8 pre-dreadnoughts and a screening force of 2 armored cruisers, 7 light cruisers, and 54 torpedo boats, departed to provide distant cover.[13] On 26 August 1914, the German light cruiser Magdeburg had run aground in the Gulf of Finland; the wreck was captured by the Russian navy, which found code books used by the German navy, along with navigational charts for the North Sea. These documents were then passed on to the Royal Navy. Room 40 began decrypting German signals, and on 14 December, intercepted messages relating to the plan to bombard Scarborough.[13] However, the exact details of the plan were unknown, and it was assumed that the High Seas Fleet would remain safely in port, as in the previous bombardment. Vice Admiral Beatty's four battlecruisers, supported by the 3rd Cruiser Squadron and the 1st Light Cruiser Squadron, along with the 2nd Battle Squadron's six dreadnoughts, were to ambush Hipper's battlecruisers.[14] During the night of 15 December, the main body of the High Seas Fleet encountered British destroyers. Fearing the prospect of a nighttime torpedo attack, Admiral Ingenohl ordered the ships to retreat.[14] Hipper was unaware of Ingenohl's reversal, and so he continued with the bombardment. Upon reaching the British coast, Hipper's battlecruisers split into two groups. Seydlitz, Moltke, and Blücher went north to shell Hartlepool, while Von der Tann and Derfflinger went south to shell Scarborough and Whitby.[15] During the bombardment of Hartlepool, Moltke was struck by a 6 in (15.2 cm) shell from a coastal battery,[7] which caused minor damage between decks, but no casualties.[15] Blücher was hit six times and Seydlitz three times by the coastal battery.[15] By 09:45 on the 16th, the two groups had reassembled, and they began to retreat eastward.[16] The High Seas Fleet's disposition on the morning of 16 December By this time, Beatty's battlecruisers were in position to block Hipper's chosen egress route, while other forces were en route to complete the encirclement. At 12:25, the light cruisers of the II Scouting Group began to pass through the British forces searching for Hipper.[17] One of the cruisers in the 2nd Light Cruiser Squadron spotted Stralsund and signaled a report to Beatty. At 12:30, Beatty turned his battlecruisers towards the German ships. Beatty presumed that the German cruisers were the advance screen for Hipper's ships, however those were some 50 km (31 mi) ahead.[17] The 2nd Light Cruiser Squadron, which had been screening for Beatty's ships, detached to pursue the German cruisers, but a misinterpreted signal from the British battlecruisers sent them back to their screening positions.[Note 4] This confusion allowed the German light cruisers to escape and alerted Hipper to the location of the British battlecruisers. The German battlecruisers wheeled to the northeast of the British forces and made good their escape.[17] Both the British and the Germans were disappointed that they failed to effectively engage their opponents. Admiral Ingenohl's reputation suffered greatly as a result of his timidity. The captain of the Moltke was furious; he stated that Ingenohl had turned back "because he was afraid of eleven British destroyers which could have been eliminated ... under the present leadership we will accomplish nothing."[18] The official German history criticized Ingenohl for failing to use his light forces to determine the size of the British fleet, stating: "he decided on a measure which not only seriously jeopardized his advance forces off the English coast but also deprived the German Fleet of a signal and certain victory."[18] Battle of Dogger Bank Main article: Battle of Dogger Bank (1915) SMS Moltke underway In early January 1915, it became known that British ships were conducting reconnaissance in the Dogger Bank area. Ingenohl was initially reluctant to destroy these forces, because the I Scouting Group was temporarily weakened while Von der Tann was in drydock for periodic maintenance. However, Konteradmiral Richard Eckermann, the Chief of Staff of the High Seas Fleet, insisted on the operation, and so Ingenohl relented and ordered Hipper to take his battlecruisers to the Dogger Bank.[19] On 23 January, Hipper sortied, with his flag in Seydlitz, followed by Moltke, Derfflinger, and Blücher, along with the light cruisers Graudenz, Rostock, Stralsund, and Kolberg and 19 torpedo boats from V Flotilla and II and XVIII Half-Flotillas. Graudenz and Stralsund were assigned to the forward screen, while Kolberg and Rostock were assigned to the starboard and port, respectively. Each light cruiser had a half-flotilla of torpedo boats attached.[19] Again, interception and decryption of German wireless signals played an important role. Although they were unaware of the exact plans, the cryptographers of Room 40 were able to deduce that Hipper would be conducting an operation in the Dogger Bank area.[19] To counter it, Beatty's 1st Battlecruiser Squadron, Rear Admiral Archibald Moore's 2nd Battlecruiser Squadron and Commodore William Goodenough's 2nd Light Cruiser Squadron were to rendezvous with Commodore Reginald Tyrwhitt's Harwich Force at 8:00 on 24 January, approximately 30 mi (48 km) north of the Dogger Bank.[19] At 08:14, Kolberg spotted the light cruiser Aurora and several destroyers from the Harwich Force.[20]Aurora challenged Kolberg with a search light, at which point Kolberg attacked Aurora and scored two hits. Aurora returned fire and scored two hits on Kolberg in retaliation. Hipper immediately turned his battlecruisers towards the gunfire, when, almost simultaneously, Stralsund spotted a large amount of smoke to the northwest of her position. This was identified as a number of large British warships steaming towards Hipper's ships.[20] Hipper turned south to flee, but was limited to 23 knots (43 km/h), which was the maximum speed of the older armored cruiser Blücher. The pursuing British battlecruisers were steaming at 27 knots (50 km/h), and quickly caught up to the German ships. At 09:52, Lion opened fire on Blücher from a range of approximately 20,000 yards (18,300 m); shortly thereafter, Queen Mary and Tiger began firing as well.[20] At 10:09, the British guns made their first hit on Blücher. Two minutes later, the German ships began returning fire, primarily concentrating on Lion, from a range of 18,000 yards (15,460 m). At 10:28, Lion was struck on the waterline, which tore a hole in the side of the ship and flooded a coal bunker.[21] At 10:30, New Zealand, the fourth ship in Beatty's line, came within range of Blücher and opened fire. By 10:35, the range had closed to 17,500 yards (16,000 m), at which point the entire German line was within the effective range of the British ships. Beatty ordered his battlecruisers to engage their German counterparts.[Note 5] However, confusion aboard Tiger led the captain to believe he was to fire on Seydlitz, which left Moltke able to fire without distraction.[21] At 10:40, one of Lion's 13.5 in (34 cm) shells struck Seydlitz causing nearly catastrophic damage that knocked out both of the rear turrets and killed 159 men.[22] Disaster was averted when the executive officer ordered the flooding of both magazines to avoid a flash fire that would have destroyed the ship.[Note 6] By this time, the German battlecruisers had zeroed in on Lion and began scoring repeated hits. At 11:01, an 11 in (28 cm) shell from Seydlitz struck Lion and knocked out two of her dynamos. At 11:18, Lion was hit by two 12 in (30 cm) shells from Derfflinger, one of which struck the waterline and penetrated the belt, allowing seawater to enter the port feed tank. This shell eventually crippled Lion by forcing the ship to turn off its engines due to seawater contamination.[22] By this time, Blücher was severely damaged after having been pounded by heavy shells. However, the chase ended when there were several reports of U-boats ahead of the British ships; Beatty quickly ordered evasive maneuvers, which allowed the German ships to increase the distance to their pursuers.[23] At this time, Lion's last operational dynamo failed, which dropped her speed to 15 knots. Beatty, in the stricken Lion, ordered the remaining battlecruisers to "Engage the enemy's rear," but signal confusion caused the ships to solely target Blücher, allowing Moltke, Seydlitz, and Derfflinger to escape.[24] By the time Beatty regained control over his ships, after having boarded Princess Royal, the German ships had too far a lead for the British to catch them; at 13:50, he broke off the chase.[25] Battle of the Gulf of Riga Main article: Battle of the Gulf of Riga On 3 August 1915, Moltke was transferred to the Baltic with I Reconnaissance Group (AG) to participate in the foray into the Riga Gulf. The intention was to destroy the Russian naval forces in the area, including the pre-dreadnought Slava, and to use the minelayer Deutschland to block the entrance to Moon Sound with naval mines. The German forces, under the command of Vice Admiral Hipper, included the four Nassau and four Helgoland battleships, the battlecruisers Moltke, Von der Tann, and Seydlitz, and a number of smaller craft.[26] On 8 August, the first attempt to clear the gulf was made; the old battleships Braunschweig and Elsaß kept Slava at bay while minesweepers cleared a path through the inner belt of mines. During this period, the rest of the German fleet remained in the Baltic and provided protection against other units of the Russian fleet. However, the approach of nightfall meant that Deutschland would be unable to mine the entrance to Moon Sound in time, and so the operation was broken off.[27] On 16 August, a second attempt was made to enter the gulf. The dreadnoughts Nassau and Posen, four light cruisers, and 31 torpedo boats breached the defenses to the gulf.[28] Nassau and Posen engaged in an artillery duel with Slava, resulting in three hits on the Russian ship that prompted her withdrawal. After three days, the Russian minefields had been cleared, and the flotilla entered the gulf on 19 August, but reports of Allied submarines in the area prompted a German withdrawal from the gulf the following day.[29] Throughout the operation, Moltke remained in the Baltic and provided cover for the assault into the Gulf of Riga. On the morning of the 19th, Moltke was torpedoed by the British E class submarine E1. The torpedo was not spotted until it was approximately 200 yards (183 m) away; without time to maneuver, the ship was struck in the bow torpedo room. The explosion damaged several torpedoes in the ship, but they did not detonate themselves. Eight men were killed, and 435 tonnes (480 short tons) of water entered the ship. The ship was repaired at Blohm & Voss in Hamburg, between 23 August and 20 September.[7] Bombardment of Yarmouth and Lowestoft Main article: Bombardment of Yarmouth and Lowestoft Moltke also took part in the bombardment of Yarmouth and Lowestoft on 24–25 April. Hipper was away on sick leave, so the German ships were under the command of Konteradmiral Friedrich Bödicker. The German battlecruisers Derfflinger, Lützow, Moltke, Seydlitz and Von der Tann left the Jade Estuary at 10:55 on 24 April, and were supported by a screening force of six light cruisers and two torpedo boat flotillas.[30] The heavy units of the High Seas Fleet sailed at 13:40, with the objective to provide distant support for Bödicker's ships. The British Admiralty was made aware of the German sortie through the interception of German wireless signals, and deployed the Grand Fleet at 15:50.[30] By 14:00, Bödicker's ships had reached a position off Norderney, at which point he turned his ships northward to avoid the Dutch observers on the island of Terschelling. At 15:38, Seydlitz struck a naval mine, which tore a 50-foot (15 m) hole in her hull, just abaft of the starboard broadside torpedo tube, allowing 1,400 short tons (1,250 long tons) of water to enter the ship.[30] Seydlitz turned back, with the screen of light cruisers, at a speed of 15 knots (28 km/h). The four remaining battlecruisers turned south immediately in the direction of Norderney to avoid further mine damage. By 16:00, Seydlitz was clear of imminent danger, so the ship stopped to allow Bödicker to disembark. The torpedo boat V28 brought Bödicker to Lützow.[31] At 04:50 on 25 April, the German battlecruisers were approaching Lowestoft when the light cruisers Rostock and Elbing, which had been covering the southern flank, spotted the light cruisers and destroyers of Commodore Tyrwhitt's Harwich Force.[31] Bödicker refused to be distracted by the British ships, and instead trained his ships' guns on Lowestoft. The German battlecruisers destroyed two 6 in (15 cm) shore batteries and inflicted other damage to the town. In the process, a single 6 in shell from one of the shore batteries struck Moltke, but the ship sustained no significant damage.[7] At 05:20, the German raiders turned north, towards Yarmouth, which they reached by 05:42. The visibility was so poor that the German ships fired one salvo each, with the exception of Derfflinger, which fired fourteen rounds from her main battery. The German ships turned back south, and at 05:47 encountered for the second time the Harwich Force, which had by then been engaged by the six light cruisers of the screening force. Bödicker's ships opened fire from a range of 13,000 yards (12,000 m).[32] Tyrwhitt immediately turned his ships around and fled south, but not before the cruiser Conquest sustained severe damage. Due to reports of British submarines and torpedo attacks, Bödicker broke off the chase and turned back east towards the High Seas Fleet. At this point, Scheer, who had been warned of the Grand Fleet's sortie from Scapa Flow, turned back towards Germany.[32] Battle of Jutland Main article: Battle of Jutland Moltke, and the rest of Hipper's battlecruisers in the I Scouting Group, lay anchored in the outer Jade Roads on the night of 30 May 1916. The following morning, at 02:00 CET,[Note 7] the ships slowly steamed out towards the Skagerrak at a speed of 16 knots (30 km/h).[33] Moltke was the fourth ship in the line of five, ahead of Von der Tann, and to the rear of Seydlitz.[33] The II Scouting Group, consisting of the light cruisers Frankfurt, Rear Admiral Bödicker's flagship, Wiesbaden, Pillau, and Elbing, and 30 torpedo boats of the II, VI, and IX Flotillas, accompanied Hipper's battlecruisers.[33] An hour and a half later, the High Seas Fleet under the command of Admiral Scheer left the Jade; the force was composed of 16 dreadnoughts.[Note 8] The High Seas Fleet was accompanied by the IV Scouting Group, composed of the light cruisers Stettin, München, Hamburg, Frauenlob, and Stuttgart, and 31 torpedo boats of the I, III, V, and VII Flotillas, led by the light cruiser Rostock. The six pre-dreadnoughts of the II Battle Squadron had departed from the Elbe roads at 02:45, and rendezvoused with the battle fleet at 5:00.[33] Shortly before 16:00, Hipper's force encountered Vice Admiral Beatty's battlecruiser squadron. The German ships were the first to open fire, at a range of approximately 15,000 yards (14,000 m).[34] When the British ships began returning fire, confusion amongst the British battlecruisers resulted in Moltke being engaged by both New Zealand and Tiger.[Note 9] The British rangefinders had misread the range to their German targets, and so the first salvos fired by the British ships fell a mile past the German battlecruisers. At 16:52, Moltke hit Tiger with two main gun shells, but neither of these hits caused any significant damage. Moltke then fired a further four shells, two of which hit simultaneously on the midships and after turrets, knocking both out for a significant period of the battle.[35] The destruction of Indefatigable Approximately 15 minutes later, the British battlecruiser Indefatigable was suddenly destroyed by Von der Tann. Shortly thereafter, Moltke fired four torpedoes at Queen Mary at a range between 11,500–10,400 yards (10,500–9,500 m).[36] This caused the British line to fall into disarray, as the torpedoes were thought to have been fired by U-boats. At this point, Hipper's battlecruisers had come into range of the V Battle Squadron, composed of the new Queen Elizabeth-class battleships, which mounted powerful 15 in (38 cm) guns. At 17:06, Barham opened fire on Von der Tann. She was joined a few minutes later by Valiant, Malaya, and Warspite; the ships concentrated their fire on Von der Tann and Moltke.[37] At 17:16, one of the 15 in shells from the fast battleships struck Moltke, where it pierced a coal bunker, tore into a casemate deck, and ignited ammunition stored therein. The explosion burned the ammunition hoist down to the magazine.[38] Von der Tann and Moltke changed their speed and direction, which threw off the aim of the V Battle Squadron and earned the battered ships a short respite.[38] While Moltke and Von der Tann were drawing the fire of the V Battle Squadron battleships, Seydlitz and Derfflinger were able to concentrate their fire on the British battlecruisers; between 17:25 and 17:30, at least five shells from Seydlitz and Derfflinger struck Queen Mary, causing a catastrophic explosion that destroyed the ship.[39] Moltke's commander, Kapitän zur See von Karpf, remarked that "The enemy's salvos lie well and close; their salvos are fired in rapid succession, the fire discipline is excellent!"[40] By 19:30, the High Seas Fleet, which was by that point pursuing the British battlecruisers, had not yet encountered the Grand Fleet. Scheer had been considering retiring his forces before darkness exposed his ships to torpedo boat attack.[41] However, he had not yet made a decision when his leading battleships encountered the main body of the Grand Fleet. This development made it impossible for Scheer to retreat, for doing so would have sacrificed the slower pre-dreadnought battleships of the II Battle Squadron, while using his dreadnoughts and battlecruisers to cover their retreat would have subjected his strongest ships to overwhelming British fire.[42] Instead, Scheer ordered his ships to turn 16 points to starboard, which would bring the pre-dreadnoughts to the relative safety of the disengaged side of the German battle line.[43] Moltke and the other battlecruisers[Note 10] followed the move, which put them astern of König.[44] Hipper's badly battered ships gained a temporary moment of respite, and uncertainty over the exact location and course of Scheer's ships led Admiral Jellicoe to turn his ships eastward, towards what he thought was the likely path of the German retreat.[45] The German fleet was instead sailing west, but Scheer ordered a second 16-point turn, which reversed course and pointed his ships at the center of the British fleet.[46] The German fleet came under intense fire from the British line, and Scheer sent Moltke, Von der Tann, Seydlitz, and Derfflinger at high speed towards the British fleet, in an attempt to disrupt their formation and gain time for his main force to retreat.[47] By 20:17, the German battlecruisers had closed to within 7,700 yards (7,040 m) of Colossus, at which point Scheer directed the ships to engage the lead ship of the British line.[48] However, three minutes later, the German battlecruisers turned in retreat, covered by a torpedo boat attack.[49] A pause in the battle at dusk allowed Moltke and the other German battlecruisers to cut away wreckage that interfered with the main guns, extinguish fires, repair the fire control and signal equipment, and ready the searchlights for nighttime action. During this period, the German fleet reorganized into a well-ordered formation in reverse order, when the German light forces encountered the British screen shortly after 21:00. The renewed gunfire gained Beatty's attention, so he turned his battlecruisers westward. At 21:09, he sighted the German battlecruisers, and drew to within 8,500 yards (7,800 m) before opening fire at 20:20.[50] The attack from the British battlecruisers completely surprised Hipper, who had been in the process of boarding Moltke from the torpedo boat G39. The German ships returned fire with every gun available, and at 21:32 hit both Lion and Princess Royal in the darkness.[51] The maneuvering of the German battlecruisers forced the leading I Battle Squadron to turn westward to avoid collision. This brought the pre-dreadnoughts of the II Battle Squadron directly behind the battlecruisers, and prevented the British ships from pursuing the German battlecruisers when they turned southward. The British battlecruisers opened fire on the old battleships; the German ships turned southwest to bring all of their guns to bear against the British ships.[51] By 22:15, Hipper was finally able to transfer to Moltke, and then ordered his ships to steam at 20 knots (37 km/h) towards the head of the German line.[52] However, only Moltke and Seydlitz were in condition to comply; Derfflinger and Von der Tann could make at most 18 knots, and so these ships lagged behind. Moltke and Seydlitz were in the process of steaming to the front of the line when the ships passed close to Stettin, which forced the ship to drastically slow down to avoid collision. This forced Frauenlob, Stuttgart, and München to turn to port, which led them into contact with the 2nd Light Cruiser Squadron; at a range of 800 yards (730 m), the cruisers on both sides pummeled each other. Rear Admiral Ludwig von Reuter decided to attempt to lure the British cruisers towards Moltke and Seydlitz. However, nearly simultaneously, the heavily damaged British cruisers broke off the attack.[53] As the light cruisers were disengaging, a torpedo fired by Southampton struck Frauenlob, and the ship exploded.[54] The German formation fell into disarray, and in the confusion, Seydlitz lost sight of Moltke. Seydlitz was no longer able to keep up with Moltke's 22 knots (41 km/h), and so detached herself to proceed to the Horns Reef lighthouse independently.[54] By 23:30 on her own, Moltke encountered four British dreadnoughts, from the rear division of the 2nd Battle Squadron. Moltke's commander Kapitän von Karpf ordered the ship to swing away, hoping he had not been detected. The British ships in fact had seen Moltke, but had decided to not to open fire in order to not reveal their location to the entire German fleet.[55] At 23:55, and again at 00:20, Kapitän von Karpf tried to find a path through the British fleet, but both times was unable to do so. It was not until 01:00, after having steamed far ahead of the Grand Fleet, that Moltke was able to made good her escape.[55] The severely damaged Seydlitz returning to port after the battle Close to the end of the battle, at 03:55, Hipper transmitted a report to Admiral Scheer informing him of the tremendous damage his ships had suffered. By that time, Derfflinger and Von der Tann each had only two guns in operation, Moltke was flooded with 1,000 tons of water, and Seydlitz was severely damaged.[56] Hipper reported: "I Scouting Group was therefore no longer of any value for a serious engagement, and was consequently directed to return to harbour by the Commander-in-Chief, while he himself determined to await developments off Horns Reef with the battlefleet."[56] During the course of the battle, Moltke had hit Tiger 13 times, and was hit herself 4 times, all by 15 in (38 cm) shells. The starboard No. 5 15 cm gun was struck by one of the 15 in shells and put out of action for the remainder of the battle. The ship suffered 16 dead and 20 wounded, the majority of which were due to the hit on the 15 cm gun. Flooding and counter-flooding efforts caused 1,000 tons of water to enter the ship.[57] Later operations During the fleet advance on 18–19 August, the I Scouting Group was to bombard the coastal town of Sunderland in an attempt to draw out and destroy Beatty's battlecruisers. As Moltke was one of only two remaining German battlecruisers still in fighting condition in the Group (Von der Tann being the other), three dreadnoughts were assigned to the Group for the operation: Markgraf, Großer Kurfürst, and the newly commissioned Bayern. Admiral Scheer and the rest of the High Seas Fleet, with 15 dreadnoughts of its own, would trail behind and provide cover.[58] The British were aware of the German plans and sortied the Grand Fleet to meet them. By 14:35, Scheer had been warned of the Grand Fleet's approach and, unwilling to engage the whole of the Grand Fleet just 11 weeks after the decidedly close call at Jutland, turned his forces around and retreated to German ports.[59] In September 1917, KzS von Karpf left Moltke; KzS Gygas assumed command of the ship. Between September and October 1917, the ship took part in Operation Albion supporting the German invasion of the Russian islands of Ösel, Dagö, and Moon (in present-day Estonia). Following the successful operation in the Baltic, Moltke was detached to support the II Reconnaissance Group (II AG), but did not actively participate in the Second Battle of Heligoland Bight.[57] Late 1917 saw the High Seas Fleet beginning to conduct anti-convoy raids in the North Sea between Britain and Norway. In October and December 1917, two British convoys to Norway were intercepted and destroyed by German cruisers and destroyers, prompting Beatty, now the Commander in Chief of the Grand Fleet, to detach several battleships and battlecruisers to protect convoys.[60] This presented to Admiral Scheer the opportunity for which he had been waiting the entire war: the chance to isolate and eliminate a portion of the Grand Fleet.[61] At 05:00 on 23 April 1918, the High Seas Fleet left harbor with the intention of intercepting one of the heavily escorted convoys. Wireless radio traffic was kept to a minimum to prevent the British from learning of the operation.[61] At 05:10 on 24 April, Moltke suffered machinery failure: the starboard propeller had fallen off the shaft, and before the turbine could be stopped, a gear wheel was destroyed.[61] The destroyed wheel flung pieces of steel into an auxiliary condenser, which flooded the engine room and stopped the operation of the center and starboard engines. Saltwater entered the boilers, reducing the ship's speed to a mere four knots; by 08:45, the captain of Moltke reported to Scheer that his ship was "out of control",[61] and that the ship would need to be towed. At 09:38, the cruiser Strassburg attempted to take the ship under tow, but was unable to do so. At 10:13, the dreadnought Oldenburg was detached from the battle fleet to tow Moltke back to port.[62] At 14:10, the convoy had still not yet been located, and so Scheer turned the High Seas Fleet back towards German waters. By 17:10, Moltke's engines had been repaired, and the ship was able to steam at a speed of 17 knots.[62] At 19:37, the British submarine E42 spotted the ship and fired a torpedo into Moltke. The ship took in 1,800 tons of water, but was able to reach harbor under her own power.[63] Repairs were carried out in Wilhelmshaven in the Imperial Dockyard, between 30 April and 9 September 1918.[62] Following repairs, Moltke took part in training operations in the Baltic from 19 September to 3 October. Starting on 1 November, the ship served as the I Scouting Group flagship for Rear Admiral von Reuter,[62] after the battlecruiser Hindenburg had gone into dry dock for repairs.[64] Fate Seydlitz leading the German battlecruisers into internment; Moltke is the second ship in the line Moltke was to have taken part in what would have amounted to the "death ride" of the High Seas Fleet shortly before the end of World War I. The bulk of the High Seas Fleet was to have sortied from their base in Wilhelmshaven to engage the British Grand Fleet; Scheer—by now the Großadmiral of the fleet—intended to inflict as much damage as possible on the British navy, in order to retain a better bargaining position for Germany, whatever the cost to the fleet.[65] However, while the fleet was consolidating in Wilhelmshaven, war-weary sailors began deserting en masse. As Von der Tann and Derfflinger passed through the locks that separated Wilhelmshaven's inner harbour and roadstead, some 300 men from both ships climbed over the side and disappeared ashore.[66] On 24 October 1918, the order was given to sail from Wilhelmshaven. Starting on the night of 29 October, sailors on several battleships mutinied; three ships from the III Squadron refused to weigh anchors, and acts of sabotage were committed on board the battleships Thüringen and Helgoland. The order to sail was rescinded in the face of this open revolt. In early November 1918, the German Revolution began; it led to the Armistice that ended the war and toppled the monarchy.[67] The vessel was surrendered with the rest of the High Seas Fleet on 24 November 1918 and interned at Scapa Flow, under the command of Kapitän-Leutnant Wollante.[68] Believing that the Treaty of Versailles had been signed and his fleet was about to be seized by the British, Rear Admiral von Reuter ordered the scuttling of the High Seas Fleet on 21 June 1919, while the British Grand Fleet was away on exercises. The ship sank in two hours and fifteen minutes.[69] Moltke was raised in 1927 and scrapped at Rosyth in 1929.[70]