Diamond
Diamond  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 (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.
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.
Material properties
A diamond is a transparent crystal of tetrahedrally bonded carbon atoms  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. 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.

Hardness
Diamond is the hardest natural material known. 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.
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 semi perfect octahedral, 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.
Somewhat related to hardness is another mechanical property toughness, which is a material's ability to resist breakage from forceful impact. 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.
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. 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.
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.
Color
Diamond has a wide band gap corresponding to the deep ultraviolet wavelength . 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 and even much less for Co. Virtually any element can be introduced to diamond by ion implantation.
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. Color in diamond has two additional sources: irradiation (usually by alpha particles), that causes the color in green diamonds; and plastic deformation of the diamond crystal lattice. Plastic deformation is the cause of color in some brown and perhaps pink and red diamonds. 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."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. 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 "" (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.

Unemployment
Unemployment as defined by the International Labor Organization occurs when people are without jobs and they have actively looked for work within the past four weeks. The unemployment rate is a measure of the prevalence of unemployment and it is calculated as a percentage by dividing the number of unemployed individuals by all individuals currently in the labor force.
There are a few types of unemployment that are used to more precisely model the effects of unemployment within the economic system. The main types of unemployment include structural unemployment which focuses on structural problems in the economy and inefficiencies inherent in labor markets including a mismatch between the supply and demand of laborers with necessary skill sets. Structural arguments emphasize causes and solutions related to disruptive technologies and globalization. Discussions of frictional unemployment focus on voluntary decisions to work based on each individual’s valuation of their own work and how that compares to current wage rates plus the time and effort required to find a job. Causes and solutions for frictional unemployment often address barriers to entry and wage rates. Behavioral economists highlight individual biases in decision making and often involve problems and solutions concerning sticky wages and efficiency wages.
History
There are limited historical records on unemployment because it has not always been acknowledged or measured systematically. Industrialization involves economies of scale that often prevent individuals from having the capital to create their own jobs to be self-employed. An individual who cannot either join an enterprise or create a job is unemployed. As individual farmers, ranchers, spinners, doctors and merchants are organized into large enterprises, those who cannot join or compete become unemployed.
Recognition of unemployment occurred slowly as economies across the world industrialized and bureaucratized
About 25 million people in the world's 30 richest countries will have lost their jobs between the end of 2007 and the end of 2010 as the economic downturn pushes most countries into recession. In April 2010, the U.S. unemployment rate was 9.9%, but the government’s broader U-6 unemployment rate was 17.1%. There are six unemployed people, on average, for each available job. Men account for at least 7 of 10 workers who lost jobs, according to Bureau of Labor Statistics data. The youth unemployment rate was 18.5% in July 2009, the highest July rate since 1948. 34.5% of young African American men were unemployed in October 2009. Officially, Detroit’s unemployment rate is 27%, but the Detroit News suggests that nearly half of this city’s working-age population may be unemployed. 3.8 million Americans lost their jobs in 2009.
The official unemployment rate in the 16 EU countries that use the euro rose to 10% in December 2009. Latvia had the highest unemployment rate in EU at 22.3% for November 2009. Europe's young workers have been especially hard hit. In November 2009, the unemployment rate in the EU27 for those aged 15–24 was 18.3%. For those under 25, the unemployment rate in Spain was 43.8%.
A flood of inexpensive consumer goods from China has recently encountered criticism from Europe, the United States and some African countries. In South Africa, some 300,000 textile workers have lost their jobs due to the influx of Chinese goods. The increasing U.S. trade deficit with China has cost 2.4 million American jobs between 2001 and 2008, according to a study by the Economic Policy Institute (EPI). A total of 3.2 million – one in six U.S. factory jobs – have disappeared between 2000 and 2007.
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