Diamonds trace elements

Evolution did not use this element, only in certain plants is it important as a trace element. The element became well-known because of heat-resistant borosilicate glasses. Boranes are chemically interesting as B-H bonds react very specifically. Perborates are used in laundry detergents (Persil). The hardness of cubic boron nitride approaches that of diamond. Amorphous (brown) boron burns very quickly and gives off much heat and is therefore used in solid-propellant rockets and in igniters in airbags. 

The primary dispersion halo and wallrock alteration around the Elura deposit was established from integrated petrographic, mineralogical and geochemical (major-, minor- and trace-element) analysis of diamond drill core samples. Seventy eight samples of variably altered and unaltered host rocks, as well as 67 near-surface weathered equivalents, were analysed for major elements using fusion disc. X-ray fluorescence analysis (XRF). Trace elements were determined by pressed powder XRF analysis. Carbonate carbon... 

Quantitative trace element analysis of diamond by LA-ICP-MS using different synthetic multielement carbon based standards (e.g., cellulose pellets) is discussed by Rege et al 2, whereby 13C was used for internal standardization. Concentrations of 41 elements were determined in two fibrous diamonds from Jwaneng Botswana (JWA 110 and 115) by relative sensitivity coefficients measured using the synthetic cellulose standard. The analytical data were verified by means of instrumental neutron activation analysis (INAA) and proton induced X-ray emission (PIXE).72... 

While we have not yet carried out detailed kinetic measurements on the rate of photocorrosion, our impression is that the process is relatively insensitive to the specific composition of the strontium titanate. Trace element compositions, obtained by spark-source mass spectrometry, are presented in Table I for the four boules of n-SrTi03 from which electrodes have been cut. Photocorrosion has been observed in samples from all four boules. In all cases, the electrodes were cut to a thickness of 1-2 mm using a diamond saw, reduced under H2 at 800-1000 C for up to 16 hours, polished with a diamond paste cloth, and etched with either hot concentrated nitric acid or hot aqua regia. Ohmic contacts were then made with gallium-indium eutectic alloy, and a wire was attached using electrically conductive silver epoxy prior to mounting the electrode on a Pyrex support tube with either epoxy cement or heat-shrinkable Teflon tubing. 

C60 has not yet been detected in primitive meteorites, a finding that could demonstrate its existence in the early solar nebular or as a component of presolar dust. However, other allotropes of carbon, diamond and graphite, have been isolated from numerous chondritic samples. Studies of the isotopic composition and trace element content and these forms of carbon suggest that they condensed in circumstellar environments. Diamond may also have been produced in the early solar nebula and meteorite parent bodies by both low-temperature-low-pressure processes and shock events. Evidence for the occurrence of another carbon allotrope, with sp hybridized bonding, commonly known as carbyne, is presented. 

Liu, Q.T., Diamond, M.L., et al (2003b) Accumulation of metals, trace elements and semi-voladle organic compounds on exterior window surfaces in Baltimore. Environmental Pollution, 122(1) 51-61. 

Much the same can be said about the diamonds, in that most minor and trace elements are radically anomalous. But the major element, carbon, has an isotopic composition within the range of solar-system normal. Moreover, the individual diamond grains are extremely small, characteristically only a few nanometers, and too small to support analysis even of carbon in individual grains. It may be that diamond carbon appears isotopically normal only because any isotopic analysis is an average over many grains. But because of the normal carbon there is persistent suspicion that most the diamonds are not really circumstellar or even presolar after all, and that the real presolar grain carrier is a small subset of the diamonds or some other phase entirely, less abundant than the diamonds but which follows them in the separation procedures. 

The known presolar/circumstellar phases diamond, silicon carbide, and graphite each contain a distinct noble-gas component which, like the major (except perhaps for carbon in diamonds), minor, and other trace elements in these phases, is radically anomalous compared to normal solar-system composition. These components are listed in Table 2 and illustrated in Figure 5. In the exploratory studies in which an understanding of these components was being developed, a variety of more-or-less complicated names, typically an acronym for some descriptive phrase or arbitrarily selected alphabetic characters (not all from the Latin alphabet), have been used. Some... 

Figure 13 Trace-element ratios in IDPs. Data from synehrotron X-ray fluoreseenee analyses are plotted on three element diagrams. Element ratios are normalized to bulk Cl abundances (element/Fe)sampie/(element/Fe)ci also denoted element/Fe/CL Cl eomposition lies at the point element/Fe/CI = 1 on eaeh plot. Averages, assuming data are normally distributed (open squares) and assuming the data are log normally distributed (open diamonds), are also shown. Plots (a)-(c) exhibit the behavior of some more refractory elements chromium, calcium, and titanium with respect to nickel, while (d) and (e) show the behavior of zine (relatively volatile) with respect to nickel (relatively refractory) and selenium (relatively volatile) (source Kehm et aL, 2002).

The P-type versus E-type paragenetic classification of diamonds based on their inclusions is introduced in Section 2.05.4.1.3. The geochemical basis for this fundamental difference between inclusion types is discussed in review articles by Meyer (1987), Harris and Gurney (1979), Gurney (1989), and Kirkley et al. (1991), summarized in brief here and discussed in the context of newer SIMS trace-element data on inclusions. Meyer (1987) points out the importance of inclusions in diamonds for the study of the mantle. First, inclusions are the chief way to understand the relationship of diamonds to their mantle host lithologies. Second, inclusions often represent pristine, geochemically unaltered samples that are not subject to the chemical re-equilibration and alteration that affects the minerals in xenoliths and macrocry sts. 

Ireland T. R., Rudnick R. L., and Spetsius Z. (1994) Trace elements in diamond inclusions from eclogites reveal hnk to Archean granites. Earth Planet. Sci. Lett. 128, 199—213. 

Pearson D. G. and Milledge H. J. (1998) Diamond growth conditions and preservation inferences from trace elements in a large garnet inclusion in a Siberian diamond. Extended Abstracts of 7th Int. Kimb. Conf., Cape Town, pp. 667-669. 

Schrauder M., Koeberl C., and Navon O. (1996) Trace element analyses of fluid-bearing diamonds from Jwaneng, Botswana. Geochim. Cosmochim. Acta 60, 4711—4724. 

Shimizu N. and Richardson S. H. (1987) Trace element abudance patterns of garnet inclusions in peridotite suite diamonds. Geochim. Cosmochim. Acta 51, 755-758. 

Stachel T. and Harris J. W. (1997) Diamond precipitation and mantle metasomatism evidence from the trace element chemistry of silicate inclusions in diamonds from Akwatia, Ghana. Contrib. Min. Petrol. 129(2-3), 143-154. 

In deeper samples, the trace-element geochemistry observed in garnet inclusions in diamonds has been attributed to carbon-bearing fluids (e.g., Stachel and Harris, 1997 Wang et al., 2000 Dobosi and Kurat, 2002), although the oxidation state of the fluid (CO2- versus CH4-rich) remains open to debate. 

Bulanova G. P., Griffin W. L., Ryan C. G., Shestakova O. Y., and Barnes S.-J. (1996) Trace elements in sulfide inclusions from Yakutian diamonds. Contrib. Mineral. Petrol. 124, 111-125. 

Wang W., Sueno S., Takahashi E., Yurimoto H., and Gasparik T. (2000) Enrichment processes at the base of the Archean lithospheric mantle observations from trace element characteristics of pyropic garnet incluisons in diamonds. Contrib. Mineral. Petrol. 139, 720-733. 

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