World Bank This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (August 2007) World Bank is a term used to describe an international financial institution that provides leveraged loans[2] to developing countries for capital programs. The World Bank has a stated goal of reducing poverty. The World Bank differs from the World Bank Group, in that the World Bank comprises only two institutions: the International Bank for Reconstruction and Development (IBRD) and the International Development Association (IDA), whereas the latter incorporates these two in addition to three more:[3] International Finance Corporation (IFC), Multilateral Investment Guarantee Agency (MIGA), and International Centre for Settlement of Investment Disputes (ICSID). History John Maynard Keynes (right) represented the United Kingdom at the conference, and Harry Dexter White (left) represented the United States. The World Bank is one of five institutions created at the Bretton Woods Conference in 1944. The International Monetary Fund, a related institution is the second. Delegates from many countries attended the Bretton Woods Conference. The most powerful countries in attendance were the United States and United Kingdom which dominated negotiations.[4] Although both are based in Washington, the World Bank is by custom headed by an American, while the IMF is led by a European. 1945–1968 From its conception until 1967 the bank undertook a relatively low level of lending. Fiscal conservatism and careful screening of loan applications was common. Bank staff attempted to balance the priorities of providing loans for reconstruction and development with the need to instill confidence in the bank.[5] Bank president John McCloy selected France to be the first recipient of World Bank aid; two other applications from Poland and Chile were rejected. The loan was for $987 million, half the amount requested and came with strict conditions. Staff from the World Bank monitored the use of the funds, ensuring that the French government would present a balanced budget and give priority of debt repayment to the World Bank over other governments. The United States State Department told the French government that communist elements within the Cabinet needed to be removed. The French Government complied with this diktat and removed the Communist coalition government. Within hours the loan to France was approved.[6] The Marshall Plan of 1947 caused lending by the bank to change as many European countries received aid that competed with World Bank loans. Emphasis was shifted to non-European countries and until 1968, loans were earmarked for projects that would enable a borrower country to repay loans (such projects as ports, highway systems, and power plants). 1968–1980 From 1968 to 1980 the bank concentrated on meeting the basic needs of people in the developing world.[citation needed] The size and number of loans to borrowers was greatly increased as loan targets expanded from infrastructure into social services and other sectors.[citation needed] These changes can be attributed to Robert McNamara who was appointed to the presidency in 1968 by Lyndon B. Johnson.[7] McNamara imported a technocratic managerial style to the Bank that he had used as United States Secretary of Defense and President of the Ford Motor Company.[8] McNamara shifted bank policy toward measures such as building schools and hospitals, improving literacy and agricultural reform. McNamara created a new system of gathering information from potential borrower nations that enabled the bank to process loan applications much faster. To finance more loans, McNamara told bank treasurer Eugene Rotberg to seek out new sources of capital outside of the northern banks that had been the primary sources of bank funding. Rotberg used the global bond market to increase the capital available to the bank.[9] One consequence of the period of poverty alleviation lending was the rapid rise of third world debt. From 1976 to 1980 developing world debt rose at an average annual rate of 20%.[10][11] 1980–1989 In 1980 A.W. Clausen replaced McNamara after being nominated by US President Jimmy Carter. Clausen replaced a large number of bank staffers from the McNamara era and instituted a new ideological focus in the bank. The replacement of Chief Economist Hollis B. Chenery by Anne Krueger in 1982 marked a notable policy shift at the bank. Krueger was known for her criticism of development funding as well as third world governments as rent-seeking states. Lending to service third world debt marked the period of 1980–1989. Structural adjustment policies aimed at streamlining the economies of developing nations (at the expense of health and social services) were also a large part of World Bank policy during this period. UNICEF reported in the late 1980s that the structural adjustment programs of the World Bank were responsible for the “reduced health, nutritional and educational levels for tens of millions of children in Asia, Latin America, and Africa”.[12] 1989–Present From 1989 World Bank policy changed in response to criticism from many groups. Environmental groups and NGOs were incorporated in the lending of the bank in order to mitigate the effects of the past that prompted such harsh criticism.[13] Bank projects "include" green concerns. The World Bank headquarters in Washington, D.C. Millennium Development Goals The World Bank's current focus is on the achievement of the Millennium Development Goals (MDGs), lending primarily to "middle-income countries" at interest rates which reflect a small mark-up over its own (AAA-rated) borrowings from capital markets; while the IDA provides low or no interest loans and grants to low income countries with little or no access to international credit markets. The IBRD is a market-based nonprofit organization, using its high credit rating to make up for the relatively low interest rate on its loans, while the IDA is funded primarily by periodic "replenishments" (grants) voted to the institution by its more affluent member countries. The Bank’s mission is to aid developing countries and their inhabitants to achieve development and the reduction of poverty, including achievement of the MDGs, by helping countries develop an environment for investment, jobs and sustainable growth, thus promoting economic growth through investment and enabling the poor to share the fruits of economic growth. Key Factors The World Bank sees the five key factors necessary for economic growth and the creation of an enabling business environment as: 1. Build capacity: Strengthening governments and educating government officials. 2. Infrastructure creation: implementation of legal and judicial systems for the encouragement of business, the protection of individual and property rights and the honoring of contracts. 3. Development of Financial Systems: the establishment of strong systems capable of supporting endeavors from micro credit to the financing of larger corporate ventures. 4. Combating corruption: Support for countries' efforts at eradicating corruption. 5. Research, Consultancy and Training: the World Bank provides platform for research on development issues, consultancy and conduct training programs (web based, on line, tele-/video conferencing and class room based) open for those who are interested from academia, students, government and non-governmental organization (NGO) officers etc. The Bank obtains funding for its operations primarily through the IBRD’s sale of AAA-rated bonds in the world’s financial markets. The IBRD’s income is generated from its lending activities, with its borrowings leveraging its own paid-in capital, plus the investment of its "float". The IDA obtains the majority of its funds from forty donor countries who replenish the bank’s funds every three years, and from loan repayments, which then become available for re-lending. Criteria Many achievements have brought the MDG targets for 2015 within reach in some cases. For the goals to be realized, six criteria must be met: stronger and more inclusive growth in Africa and fragile states, more effort in health and education, integration of the development and environment agendas, more and better aid, movement on trade negotiations, and stronger and more focused support from multilateral institutions like the World Bank. 1. Eradicate Extreme Poverty and Hunger: From 1990 through 2004, the proportion of people living in extreme poverty fell from almost a third to less than a fifth. Although results vary widely within regions and countries, the trend indicates that the world as a whole can meet the goal of halving the percentage of people living in poverty. Africa’s poverty, however, is expected to rise, and most of the 36 countries where 90% of the world’s undernourished children live are in Africa. Less than a quarter of countries are on track for achieving the goal of halving under-nutrition. 2. Achieve Universal Primary Education: The number of children in school in developing countries increased from 80% in 1991 to 88% in 2005. Still, about 72 million children of primary school age, 57% of them girls, were not being educated as of 2005. 3. Promote Gender Equality and Empower Women: The tide is turning slowly for women in the labor market, yet far more women than men- worldwide more than 60% - are contributing but unpaid family workers. The World Bank Group Gender Action Plan was created to advance women’s economic empowerment and promote shared growth. 4. Reduce Child Mortality: There is some improvement in survival rates globally; accelerated improvements are needed most urgently in South Asia and Sub-Saharan Africa. An estimated 10 million-plus children under five died in 2005; most of their deaths were from preventable causes. 5. Improve Maternal Health: Almost all of the half million women who die during pregnancy or childbirth every year live in Sub-Saharan Africa and Asia. There are numerous causes of maternal death that require a variety of health care interventions to be made widely accessible. 6. Combat HIV/AIDS, Malaria, and Other Diseases: Annual numbers of new HIV infections and AIDS deaths have fallen, but the number of people living with HIV continues to grow. In the eight worst-hit southern African countries, prevalence is above 15 percent. Treatment has increased globally, but still meets only 30 percent of needs (with wide variations across countries). AIDS remains the leading cause of death in Sub-Saharan Africa (1.6 million deaths in 2007). There are 300 to 500 million cases of malaria each year, leading to more than 1 million deaths. Nearly all the cases and more than 95 percent of the deaths occur in Sub-Saharan Africa. 7. Ensure Environmental Sustainability: Deforestation remains a critical problem, particularly in regions of biological diversity, which continues to decline. Greenhouse gas emissions are increasing faster than energy technology advancement. 8. Develop a Global Partnership for Development: Donor countries have renewed their commitment. Donors have to fulfill their pledges to match the current rate of core program development. Emphasis is being placed on the Bank Group’s collaboration with multilateral and local partners to quicken progress toward the MDGs’ realization. Leadership The President of the Bank, currently Robert B. Zoellick, is responsible for chairing the meetings of the Boards of Directors and for overall management of the Bank. Traditionally, the Bank President has always been a US citizen nominated by the United States, the largest shareholder in the bank. The nominee is subject to confirmation by the Board of Governors, to serve for a five-year, renewable term.[14] The Executive Directors, representing the Bank's member countries, make up the Board of Directors, usually meeting twice a week to oversee activities such as the approval of loans and guarantees, new policies, the administrative budget, country assistance strategies and borrowing and financing decisions. The Vice Presidents of the Bank are its principal managers, in charge of regions, sectors, networks and functions. There are 24 Vice-Presidents, three Senior Vice Presidents and two Executive Vice Presidents. Members Main article: List of World Bank members The International Bank for Reconstruction and Development (IBRD) has 186 member countries, while the International Development Association (IDA) has 168 members.[15] Each member state of IBRD should be also a member of the International Monetary Fund (IMF) and only members of IBRD are allowed to join other institutions within the Bank (such as IDA).[16] Poverty reduction strategies For the poorest developing countries in the world, the bank’s assistance plans are based on poverty reduction strategies; by combining a cross-section of local groups with an extensive analysis of the country’s financial and economic situation the World Bank develops a strategy pertaining uniquely to the country in question. The government then identifies the country’s priorities and targets for the reduction of poverty, and the World Bank aligns its aid efforts correspondingly. Forty-five countries pledged US$25.1 billion in "aid for the world's poorest countries", aid that goes to the World Bank International Development Association (IDA) which distributes the gifts to eighty poorer countries. While wealthier nations sometimes fund their own aid projects, including those for diseases, and although IDA is the recipient of criticism, Robert B. Zoellick, the president of the World Bank, said when the gifts were announced on December 15, 2007, that IDA money "is the core funding that the poorest developing countries rely on".[17] Clean Technology Fund management The World Bank has been assigned temporary management responsibility of the Clean Technology Fund (CTF), focused on making renewable energy cost-competitive with coal-fired power as quickly as possible, but this may not continue after UN's Copenhagen climate change conference in December, 2009, because of the Bank's continued investment in coal-fired power plants.[18] Country assistance strategies As a guideline to the World Bank's operations in any particular country, a Country Assistance Strategy is produced, in cooperation with the local government and any interested stakeholders and may rely on analytical work performed by the Bank or other parties. Criticism The World Bank has long been criticized by non-governmental organizations, such as the indigenous rights group Survival International, and academics, including its former Chief Economist Joseph Stiglitz who is equally critical of the International Monetary Fund, the US Treasury Department, US and other developed country trade negotiators.[19] Critics argue that the so-called free market reform policies which the Bank advocates are often harmful to economic development if implemented badly, too quickly ("shock therapy"), in the wrong sequence or in weak, uncompetitive economies.[20][21] In Masters of Illusion: The World Bank and the Poverty of Nations (1996), Catherine Caufield argued that the assumptions and structure of the World Bank harms southern nations. Caufield criticized its formulaic recipes of "development". To the World Bank, different nations and regions are indistinguishable and ready to receive the "uniform remedy of development". She argued that to attain even modest success, Western practices are adopted and traditional economic structures and values abandoned. A second assumption is that poor countries cannot modernize without money and advice from abroad. A number of intellectuals in developing countries have argued that the World Bank is deeply implicated in contemporary modes of donor and NGO imperialism, and that its intellectual contributions function to blame the poor for their condition.[22] One of the strongest criticisms of the World Bank has been the way in which it is governed. While the World Bank represents 186 countries, it is run by a small number of economically powerful countries. These countries choose the leadership and senior management of the World Bank, and so their interests dominate the bank.[23] The World Bank has dual roles that are contradictory: that of a political organization and that of a practical organization. As a political organization, the World Bank must meet the demands of donor and borrowing governments, private capital markets, and other international organizations. As an action-oriented organization, it must be neutral, specializing in development aid, technical assistance, and loans. The World Bank’s obligations to donor countries and private capital markets have caused it to adopt policies which dictate that poverty is best alleviated by the implementation of "market" policies.[24] In the 1990s, the World Bank and the IMF forged the Washington Consensus, policies which included deregulation and liberalization of markets, privatization and the downscaling of government. Though the Washington Consensus was conceived as a policy that would best promote development, it was criticized for ignoring equity, employment and how reforms like privatization were carried out. Many now agree[citation needed] that the Washington Consensus placed too much emphasis on the growth of GDP, and not enough on the permanence of growth or on whether growth contributed to better living standards.[25] Some analysis shows that the World Bank has increased poverty and been detrimental to the environment, public health and cultural diversity.[26] Some critics also claim that the World Bank has consistently pushed a neoliberal agenda, imposing policies on developing countries which have been damaging, destructive and anti-developmental.[27][28] It has also been suggested that the World Bank is an instrument for the promotion of US or Western interests in certain regions of the world. Even South American nations have established the Bank of the South in order to reduce US influence in the region.[29] Criticism of the bank, that the President is always a citizen of the United States, nominated by the President of the United States (though subject to the "approval" of the other member countries). There have been accusations that the decision-making structure is undemocratic as the US has a veto on some constitutional decisions with just over 16% of the shares in the bank;[30] Decisions can only be passed with votes from countries whose shares total more than 85% of the bank's shares.[31] A further criticism concerns internal management and the manner in which the World Bank is said to lack accountability.[32] Criticism of the World Bank often takes the form of protesting as seen in recent events such as the World Bank Oslo 2002 Protests,[33] the October Rebellion,[34] and the Battle of Seattle.[35] Such demonstrations have occurred all over the world, even amongst the Brazilian Kayapo people.[36] In 2008, a World Bank report which found that biofuels had driven food prices up 75% was not published. Officials confided that they believed it was suppressed to avoid embarrassing the then-President of the United States, George W. Bush.[37] The World Bank has also been criticized for not publishing reports related to the Palestinian economic situation in the West Bank and Gaza. Economists in the region have often written damning reports of the Israeli occupation and its effects on the economy, but these reports remain internal and are not published. Knowledge production The World Bank has been criticised for the manner in which it engages in “the production, accumulation, circulation and functioning” of knowledge. The Bank’s production of knowledge has become integral to the funding and justification of large capital projects. The Bank relies on “a growing network of translocal scientists, technocrats, NGOs, and empowered citizens to help generate data and construct discursive strategies”.[38] Its capacity to produce authoritative knowledge is a response to intense scrutiny of Bank projects resulting from the successes of growing anti-Bank and alternative-development movements.[39] “Development has relied exclusively on one knowledge system, namely, the modern Western one. The dominance of this knowledge system has dictated the marginalization and disqualification of non-Western knowledge systems”.[40] It has been remarked that in these alternative knowledge systems, researchers and activists might find alternative rationales to guide interventionist action away from Western (Bank-produced) ways of thinking. Knowledge production has become an asset to the Bank, and “it is generated and used in highly strategic ways”[39] to provide justifications for development. Structural adjustment The effect of structural adjustment policies on poor countries has been one of the most significant criticisms of the World Bank. The oil crisis in the late 1970s plunged many countries into economic crises.[41] The World Bank responded with structural adjustment loans which distributed aid to struggling countries while enforcing policy changes in order to reduce inflation and fiscal imbalance. Some of these policies included encouraging production, investment and labour-intensive manufacturing, changing real exchange rates and altering the distribution of government resources.[42] Structural adjustment policies were most effective in countries with an institutional framework that allowed these policies to be implemented easily.[42] For some countries, particularly in Sub-Saharan Africa, economic growth regressed and inflation worsened.[42] The alleviation of poverty was not a goal of structural adjustment loans, and the circumstances of the poor often worsened, due to a reduction in social spending and an increase in the price of food, as subsidies were lifted.[42] By the late 1980s, international organizations began to admit that structural adjustment policies were worsening life for the world’s poor. The World Bank changed structural adjustment loans, allowing for social spending to be maintained, and encouraging a slower change to policies such as transfer of subsidies and price rises.[43] In 1999, the World Bank and the IMF introduced the Poverty Reduction Strategy Paper approach to replace structural adjustment loans.[44] The Poverty Reduction Strategy Paper approach has been interpreted as an extension of structural adjustment policies as it continues to reinforce and legitimize global inequities.[45] Neither approach has addressed the inherent flaws within the global economy that contribute to economic and social inequities within developing countries.[46] By reinforcing the relationship between lending and client states, many believe that the World Bank has usurped indebted countries' power to determine their own economic policy.[47] Water privatization Sociologist Michael Goldman has argued that “Industry analysts predict that private water will soon be a capitalized market as precious, and as war-provoking, as oil”.[48] Goldman says “These days, an indebted country cannot borrow capital from the World Bank or IMF without a domestic water privatization policy as a precondition”.[49] The Bank is utilizing “the 'Washington Consensus' model of "development" to promote water privatization. Following this model, the World Bank is forcing many countries to commodify their water resources, rather than using their expertise in the public sector to acknowledge water as a universal human right and an essential public service”.[50] The push for water privatization development plays upon “the shocking tragedy that much of the world lacks affordable clean water”. This image creates “new opportunities in development, though it may have little to do with ultimately quenching” the needs of impoverished countries. “The problem of water scarcity for the world’s poor has been analyzed by the World Bank as one in which the public sector has failed to deliver, and has therefore prevented development from “taking off”, and the economy from modernizing. If the state cannot deliver something as basic as water and sanitation, the argument goes, it is a strong indication of a general failure of public-sector capacity”.[51] However, “with the sale or lease of a public good comes more than simply a privatized service; alongside it comes a wide set of postcolonial institutional forces that intervene in state-citizen relations and North-South dynamics”.[52] Business and political interests of main stakeholders Although controversial and far from proven, there is criticism that World Bank and IMF are used as a means to fulfill business (interests of large corporations to enter the natural resource markets of the country and obtain the legal guarantees that it can stay there) or political needs of the main IMF donors (mostly USA), that were previously historically obtained by more direct activity - war, economic blockade, espionage. See for example Confessions of an Economic Hit Man. Sovereign immunity Despite claiming goals of “good governance and anti-corruption?[53] the World Bank requires sovereign immunity from countries it deals with.[54][55][56][57][58] Sovereign immunity waives a holder from all legal liability for their actions. It is proposed that this immunity from responsibility is a “shield which [The World Bank] wants resort to, for escaping accountability and security by the people.”[54] As the United States has veto power, it can prevent the World Bank from taking action against its interests.[54] Environmental strategy The World Bank's ongoing work to develop a strategy on climate change and environmental threats has been criticized for (i) lacking of a proper overall vision and purpose, (ii) having a limited focus on its own role in global and regional governance, and (iii) having limited recognition of specific regional issues, e.g. issues of rights to food and land, and sustainable land use. Critics have also commented that only 1% of the World Bank's lending goes to the environmental sector, narrowly defined.[59]

When we offered moms a chance to vent about their mothers-in-law, their response was immediate, intense, and, frankly, a little insecure. "Whatever you do, maintain my anonymity," women said over and over, as they cut loose with gripes over behavior ranging from the mildly annoying to the downright destructive. Now, we're not suggesting that YOUR MILs are guilty of any of the things these moms complained about, but just FYI, here's a roundup of some of the things that OTHER grandmothers do.

1. Parenting advice? Thanks, but no thanks

If I'm looking for tips, I've got plenty of resources — including friends, my pediatrician, and most important, your son. Unless we specifically ask for your opinion, let the two of us figure it out. We want to raise the kids our own way — mistakes and all.

2. Passive aggressive is still aggressive

That story you love to tell about the homemade dinners your son came home to as a child always seems perfectly timed to coincide with my bringing out a store-bought dessert. Oh, and that can of Bar Keepers Friend you gifted me for Christmas? I got the hint. Very subtle.

3. I don't HAVE to pick up after everyone

You know how you always say you didn't spoil your son growing up? You're wrong. My housekeeping skills may not be up to your standards but I know there's at least one thing that I do differently than you that I'm handling right — teaching my kids to clean up after themselves.

4. Let's stop standing on ceremony

I know it bothered you that I didn't send you a thank-you note for hosting my parents at your home, but I wasn't being an ingrate. It's just that I had started to think of us all as one clan, not as each other's house guests.

5. Mi casa is not your casa

So stop showing up uninvited, unannounced, and unable to understand that I like my kitchen organized the way it is.

6. Yes, I am good enough for him

It's sweet that you still think your son is perfect, as long as you also understand that, despite what you may think, I'm also perfect for him.

7. Babysit much? Oh, you really think so?

You love to tell your friends how much you enjoy spending time with your grandkids, but when I ask you to help me out and watch them, you act like I have inconvenienced you — yet again. I'm not suggesting you give up your busy life. On the other hand, the children won't be this little for long — you of all people should realize that.

8. Money can't buy you love

At birthdays and holidays, please ask us for some gift ideas and limits. And if you really think the kids need the latest and greatest video-game system, fine — as long as you keep it at your house.

9. Sorry, I'm nothing like you

But that doesn't mean I don't respect the heck out of you. If you don't believe me, consider this the ultimate compliment — I married your son knowing full well that, as the saying goes, "you marry the whole family."

10. Thank you!

Thank you for raising such a decent, responsible, kind man ... but why couldn't you have given him your great sense of style?

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.