In recent years consumers, NGOs, and governments alike have become increasingly concerned about the problem of `conflict¿ or `blood¿ diamonds in relation to on-going armed conflicts in Angola, Sierra Leone, and the Democratic Republic of Congo (DRC). Allegations by NGOs, governments and the UN that many conflicts are fuelled by illicit exports of diamonds have begun to be acknowledged by the diamond industry. Diamonds, and the money they generate, have been used to purchase arms, ammunition, uniforms and other equipment, as well as to pay soldiers and to cultivate strategic alliances for those armed groups in control of territory rich in this lucrative resource. This has facilitated the intensification and protraction of violent conflicts in Africa. Additionally, the wealth to be gained from the illicit extraction and sale of diamonds has contributed to the prominence of economic agendas in many civil wars that motivate faction leaders to continue the conflict in order to protect their businesses.1 For example, the Angolan rebel group UNITA (União Nacional para a Inedepência Total de Angola) is believed to have received US$3.7 billion in a six year period during the 1990s - a far greater amount than the foreign aid received from patrons like the United States and South Africa during the Cold War. This money has both funded large scale arms purchases and swelled the personal coffers of UNITA leaders, thereby contributing to the intransigence of those leaders in agreeing and implementing peace and facilitating continued violence.2 In Sierra Leone the Revolutionary United Front (RUF) has funded its arms acquisitions with illicit diamond revenues and the extraction of diamonds is seen as one of the main factors behind the lack of implementation of the Lomé peace accord and the subsequent resurgence of violence. In the Democratic Republic of Congo (DRC) both the government and rebel forces have financed their war efforts through the diamond trade, as have some of the intervening regional powers. As a result the fighting around diamond rich areas and trading centres has been particularly intense. For example, in spite of a unilateral ceasefire declared by Rwanda on the 29th of May 1999, it is believed to have sent 7,000 fresh troops to the DRC in June as the battle for the diamond rich area of Mbuji-Mayi escalated. However the prominence of `conflict diamonds¿ in the policy discourse related to these conflicts and their resolution has served to obscure a range of other issues which are equally, if not more, central to finding lasting solutions to these wars. In spite of the fact that the arms flows which sustain these conflicts are only partly financed by `conflict diamonds¿ they are often only mentioned as one aspect of the illegal diamond trade rather than as a core issue. Even more concerning, perhaps, is that the discourse of `greed¿ rather than `grievance¿ as the foundation and driving force of conflicts obscures the complexity of political, social, and other economic dimensions of these wars. Thus, while efforts to reduce the conflict diamond trade may be an essential element of the resolution of these conflicts, other factors of potentially greater import are pushed down the agendas of many of the governments and NGOs whose input into those processes may be the key to success. In short, therefore, the issue 2 of conflict diamonds is one aspect of the complex dynamics and processes of ongoing African conflicts, not vice-versa.

A method was investigated to synthesize diamonds at atmospheric pressure without the use of diamond seed crystals. The method was first proposed by Burton in 1905 and appears to have been lost in the literature. The procedure is based on Ostwald's principle of the formation of metastable, intermediate crystals en route to a more-stable final product. Carbon was dissolved in a lead-calcium alloy and was later precipitated out of the melt by the removal of calcium with steam. The calcium was used to increase the solubility of carbon in lead. Reaction temperatures between 775 K and 1025 K were used. The resulting precipitate, analyzed by both chemical and physical means, was found to be well-crystallized graphite. No diamond formation was found to occur. / Master of Science

X-ray diffraction topography, using both conventional and synchrotron sources, has been employd t reveal, to a resoltuoon of 1um, internal structural imperfections in diamonds from Brazil. Many of these diamonds were found to be twinned; and X-ray studies have been made of twinned diamonds from Brazil and elsewhere, in order to elucidate the mechanisms of twinning in diamond. Numerous X-ray topographs have been taken of contact twins (mcles), interpenetrant cubes and mulitple twins. The well collimated beam of synchrotron radiation at the SERV Daresbury Laboratory has proved most useful in revealing, in the forward reflexion Laue photographers, small twinned regions of diamons: the presence of which would have been mised by conventioanl methods.

A survey of the optical and electron paramagnetic resonance (E.F.R.) absorption in a large number of diamonds from all major sources of production has revealed that perfect diamond is virtually non-existent. One or more of eleven different types of defect centres is found in each specimen. The presence or absence of nitrogen has long been known to give rise to the distinctive properties of Type I and Type II diamond.The present survey has shown that the form in which the nitrogen is present is significant. In most specimens the nitrogen is present in substitutional, non-paramagnetic platelet form, and these specimens were classified as Type Ia diamonds. A small group of transparent natural diamonds was found to contain dispersed paramagnetic nitrogen. The optical properties of these diamonds are unlike those of other diamond types and have hitherto not been reported. It is proposed that these diamonds be classified as Type lb.Three new systems of E.P.R. lines were found in Type Ib diamond. They are shown to be due to: (i) 13C atoms situated in different positions relative to the substitutional nitrogen, (ii) interaction of the small quadrupole moment of the nitrogen with the electric field gradient, and (iii) the presence of the l5N isotope. Synthetic diamonds are found to be exclusively of the Type Ib variety, whereas natural Type Ib diamond are rare exceptions. This is attributed to the growth history of the specimens. In order to investigate the defect centres associated with nitrogen in diamond, Type Ia and Ib diamond were irradiated with 0.78 MeV electrons. The effects observed were complicated and therefore led to a general investigation of irradiation damage, and the annealing of irradiation damage in diamond. In addition to the G.R.l and U.V. bands induced in all diamond by irradiation damage, another optical absorption feature, the N.D.l band, is found in all Type Ia diamond after irradiation and limited heating. It is suggested that the N.D.l centre arises from the combination of a carbon interstitial, and nitrogen in platelet form, and that the other primary product of irradiation damage, a vacancy, is responsible for both the G.R.l and U.V. bands. The N.D.l centre acts as an acceptor, the G.R.l centre as a donor. In the ionized state G.R.l is inactive in optical absorption; N.D.l is active. Electron transfer by thermal excitation results in the bleaching of G.R.l and the enhancement of N.J.l. Illumination with light in the N.D.l band causes electron transfer in the reverse direction, restoring band strengths to their former condition. A model is proposed which defines the energies within the forbidden gap of the ground and excited states of G.R.l and N.D.l. On heat treatment at temperatures of 500°C and above, the G.R.l band in all diamonds anneals out. The rate of annealing, however, is founa to be dependent on the nitrogen concentration. Thus in Type IIa diamond (which contains no nitrogen) G.R.l anneals very slowly, resulting in the formation of an absorption tail. In Type Ia diamond G.R.l anneals much faster (the actual rate depending on the nitrogen concentration), and two optical absorption bands, 5032A and H2, are formed. It is proposed that the vacancy in diamond becomes mobile at about 500° C, and that the G.R.l band in Type IIa diamond anneals because of the agglomeration of vacancies, which results in the formation of defects responsible for the absorption tail. In Type Ia diamond the nitrogen platelets are ideal sinks for vacancies, because the lattice on either side of a platelet is in compression. G.R.l therefore anneals more rapidly and 5032A centres are formed due to the combination of a vacancy and a nitrogen platelet. The nature of the H2 centre is much more obscure, but a possible explanation is that H2 centres are formed in addition, because the N.D.l centres (nitrogen platelets with embedded interstitials) also succeed in trapping vacancies. Vacancy/interstitial recombinations are prevented since these defects are pinned to different locations in the platelet region. In type Ib diamonds N. D.l centres were found to form at a lower temperature than in Type Ia diamond. It is suggested that the carbon interstitial in diamond is mobile, and combines with Substitutional nitrogen in isolated positions at temperatures below 250°C. In Type Ia specimens, where the nitrogen is segregated in platelets, this process only occurs at about 250°C, when the interstitial has enough kinetic energy to overcome the energy barrier preventing it from combining with nitrogen inside the platelet region where it will relieve strain. Because of the different substitutional nitrogen configuration, the energy levels of N.D.l centres in Type Ib diamond are such that electron transfer by thermal excitation from G.R.l to N.D.l occurs at room temperature. Most of the G.R.l centres are therefore permanently ionized and optically inactive. After heat treatment, a new band called the 6400A band is formed in irradiated Type Ib diamond. It is suggested that 6400A centres are formed by the combination of mobile vacancies with substitutional nitrogen in isolated positions. The 6400A band is therefore analogous to the 5032A band produced in Type Ia diamond. As expected no analogue of the H2 is formed in Type Ib diamond, as both an interstitial and a vacancy cannot co-exist in combination with a single isolated substitutional nitrogen atom.

Diamonds in the Rough is a dramatic coming-of-age novel, chronicling the experiences of college student Sofia Dayan. The intricacies of the Forty-Seventh Street diamond exchange are revealed during Sofia's time as an office assistant to a Hassidic diamond dealer, and she slowly discovers that her boss is involved in an illicit transaction concerning her father. Also coping with the symptoms of a newly diagnosed illness, rheumatoid arthritis, she begins a relationship with David Cohen - her father's former friend and business associate. Tensions build as Sofia manages her disease, attempts to strengthen her bond with David, and discovers what her father and boss are conspiring. Like a diamond, all the characters within the story are flawed beneath the surface and, to some degree, are living in illusions. Visual art and music enhance this primary theme; both often depict something beautiful but contain a darker subtext. / by Efrat Friedman. / Thesis (M.F.A.)--Florida Atlantic University, 2010. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web. FboU

Physics / D.Phil (Physics)

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The sub-surface region of chemical vapour deposition (CVD) diamond was transformed by C+ ion implantation followed by isochronal annealing up to 1200 oC. Different implantation regimes and with different energies at different implantation temperatures would give different thicknesses were studied. This enabled a study in the evolution of the stiffness of the damaged layer as a function of annealing. The technique of choice for this study was the non-destructive Brillouin light scattering (BLS) utilizing two scattering geometries; indirectly scattered phonons (Kr¨uger-type geometry) for temperature anneals up to 600 oC, and the conventional surface ripple mechanism up to 1200 oC. It has been argued that surface acoustic waves (SAW) on a transparent medium are enhanced by applying a thin metallic reflective layer on the surface, this study has showed that opacity of the substrate is key. In fact, bulk modes with SAW-like characteristics emanating from indirect photon scattering off phonons after reflection at the smooth reflective back of the sample dominated down to transmission below 5% which was observed after annealing between 500-600 oC (low annealing temperatures). The other complementing techniques employed to understand the changing structure of the ion implanted diamond were Raman spectroscopy, electromagnetic transmission in the visible range, electron energy loss spectroscopy (EELS) and high-resolution transmission electron microscopy (HRTEM) in addition to theoretical techniques: transport of ions in matter (TRIM), finite element modelling (FEM) and elastodynamic Green’s functions. Although the electronic techniques showed a structurally changing material at the low annealing temperatures, the optical ones did not show significant changes in the ion-damaged material possibly due to lack of distinct interface between the pristine diamond and the ion irradiated region at these lower annealing temperatures.