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The Sheahan Diamond Literature Reference Compilation - Scientific and Media Articles based on Major Keyword - Diamond - Crystallography
The Sheahan Diamond Literature Reference Compilation is compiled by Patricia Sheahan who publishes on a monthly basis a list of new scientific articles related to diamonds as well as media coverage and corporate announcements called the Sheahan Diamond Literature Service that is distributed as a free pdf to a list of followers. Pat has kindly agreed to allow her work to be made available as an online digital resource at Kaiser Research Online so that a broader community interested in diamonds and related geology can benefit. The references are for personal use information purposes only; when available a link is provided to an online location where the full article can be accessed or purchased directly. Reproduction of this compilation in part or in whole without permission from the Sheahan Diamond Literature Service is strictly prohibited. Return to Diamond Keyword Index
Sheahan Diamond Literature Reference Compilation - Scientific Articles by Author for all years
Each article reference in the SDLRC is tagged with one or more key words assigned by Pat Sheahan to highlight the main topics of the article. In an effort to make it easier for users to track down articles related to a specific topic, KRO has extracted these key words and developed a list of major key words presented in this Key Word Index to which individual key words used in the article reference have been assigned. In most of the individual Key Word Reports the references are in crhonological order, though in some such as Deposits the order is first by key word and then chronological. Only articles classified as "technical" (mainly scientific journal articles) and "media" (independent media articles) are included in the Key Word Index. References that were added in the most recent monthly update are highlighted in yellow.
Diamond - Crystallography deals with the different crystal forms of diamond as well as the science of Crystallography which deals with how atoms are arranged in crystals.
Cr- Rich Spinel and Garnet in Two Peridotite Xenoliths From the Frank Smith Mine South Africa: Significance of Al and Chromium Distribution between Spinel and Garnet.
Howell, D., Stern, R.A., Griffin, W.L., Southworth, R., Mikhail, S., Stachel, T., Verchovsky, A.B., O'Reilly, S.Y., Pearson, N.J.
New thermodynamic models and calculated phase equilibration temperatures in NCFMAS for basic and ultrabasic compositions through the transition zone into the uppermost lower mantle.
Journal of Physics Condensed Matter, Vol. 541, 1, pp. 12090-12094.
Technology
Diamond crystallography
Abstract: The optical and ODMR spectra of nitrogen vacancy (NV) centers in diamond were investigated as applied to the development of micro-scale diamond magnetometer sensor. It is shown that the NV0 center (unlike the NV? center) has an absorption line in the UV range. The inversion of the zero phonon line of the NV? center was observed and explained. ODMR signals in high magnetic fields (as compared with inner fields in the crystal) as well as in weak fields also were investigated. We propose the solution to the problem of the magnetometer sensitivity reduction at low magnetic field, that is of interest for quantum magnetometry applications. Peculiarities of optical and ODMR Spectra of Nitrogen-Vacancy Color Centers in Diamond Crystals.
Doklady Earth Sciences, Vol. 471, 2, pp. 1303-1306.
Technology
Diamond crystallography
Abstract: The occurrence rates of combinatorial types of simple polyhedra {111} are analyzed for natural and artificial diamonds. The empirical occurrence rates of 14 possible polyhedra in an isotropic environment are obtained based on numeral simulation of growth forms of octahedral crystals by the Monte-Carlo method. The phenomenon of dissymmetrization by Curie’s principle related to the crystallization conditions is established for artificial and natural diamonds.
Geochemistry International, Vol. 55, 12, pp. 1193-1203.
Russia
diamond - crystallography
Abstract: In this paper, we consider an ontogenic model for the formation of morphological types of growth and dissolution of cubic diamonds of variety II by Yu.L. Orlov from placers of the Anabar diamondiferous region. The following ontogenic domains of crystals and corresponding evolutionary stages of growth accompanying a general decrease in supersaturation in the crystallization medium were distinguished: microblock mosaic cuboids with defects produced by the mechanism of rotational plastic deformation-cuboids with linear translation deformations-cuboids and antiskeletal growth forms of cuboids composed of octahedral growth layers-pseudocubic growth forms of a flat-faced octahedron. The crystal morphological evolution of cuboids during the bulk dissolution of individuals in fluid-bearing melt transporting them to the surface was traced. The investigation of transitional forms of cuboid diamond dissolution showed that the final form of diamond dissolution is a rounded tetrahexahedroid independent of the combination of cuboid faces with subordinate faces of octahedron, rhombododecahedron, and tetrahexahedron observed on resorbed crystals of cubic habit. It was found that the final stages of cuboid dissolution produced disk-shaped microrelief features on the diamond surface in the form of randomly distributed ideal rounded etch pits resulting from interaction with microscopic cavitation gas bubbles released during the decompression of ascending kimberlite melt.
Abstract: Facets that are nearly parallel to a diamond’s octahedral crystal plane often develop a wavy, rippled appearance called "lizard skin" during polishing (e.g., J.I. Koivula, The MicroWorld of Diamonds, Gemworld International, Northbrook, Illinois, 2000, p. 63). The term is also used more broadly to describe any bumpy, uneven surface texture that develops on polished diamond facets. It is often attributed to polishing off-grain. Recently, GIA’s New York lab encountered a 2.67 ct type IIa diamond (figure 1, left) with especially prominent lizard skin texture on multiple facets (figure 1, center and right). In this case, the texture appears to have developed due to a preexisting deformation fabric or structure inherent to the diamond itself, rather than merely as a consequence of poor polishing technique.
Abstract: Recent advances in classical density functional theory are combined with stochastic process theory and rare event techniques to formulate a theoretical description of nucleation, including crystallization, that can predict nonclassical nucleation pathways based on no input other than the interaction potential of the particles making up the system. The theory is formulated directly in terms of the density field, thus forgoing the need to define collective variables. It is illustrated by application to diffusion-limited nucleation of macromolecules in solution for both liquid-liquid separation and crystallization. Both involve nonclassical pathways with crystallization, in particular, proceeding by a two-step mechanism consisting of the formation of a dense-solution droplet followed by ordering originating at the core of the droplet. Furthermore, during the ordering, the free-energy surface shows shallow minima associated with the freezing of liquid into solid shells, which may shed light on the widely observed metastability of nanoscale clusters.
Abstract: Although hydrogen is the most abundant element in the solar system, the mechanisms of exchange of this element between the deep interior and surface of Earth are still uncertain. Hydrogen has profound effects on properties and processes on microscopic-to-global scales. Here we report the discovery of the first hydride (VH2) ever reported in nature. This phase has been found in the ejecta of Cretaceous pyroclastic volcanoes on Mt Carmel, N. Israel, which include abundant xenoliths containing highly reduced mineral assemblages. These xenoliths were sampled by their host magmas at different stages of their evolution but are not genetically related to them. The xenoliths are interpreted as the products of extended interaction between originally mafic magmas and CH4+H2 fluids, derived from a deeper, metal-saturated mantle. The last stages of melt evolution are recorded by coarse-grained aggregates of hibonite (CaAl12O19) + grossite (CaAl4O7) + V-rich spinels ± spheroidal to dendritic inclusions of metallic vanadium (V0), apparently trapped as immiscible metallic melts. The presence of V0 implies low oxygen fugacities and suggests crystallization of the aggregates in a hydrogen-rich atmosphere. The presence of such reducing conditions in the upper mantle has major implications for the transport of carbon, hydrogen and other volatile species from the deep mantle to the surface.
Abstract: We have investigated a diamond crystal that consists of several misorientated subgrains. The main feature of the crystal is the dark in the cathodoluminescence core that has “estuary-like” boundaries extending along the subgrain interfaces. The core has more than 3100 ppm of nitrogen, and the share of the B form is more than 95%; the absorbance of the centre N3VH at 3107 cm -1 reaches 75 cm-1. The N3 centre’s absorbance, as well as N3 luminescence, is absent in the core. In the outer part of the crystal, the bright blue luminescence of the N3 centre is registered, and the N3 absorbance reaches 5.3 cm-1. These observations may be explained by the conversion of N3 centres to N3VH after attaching a hydrogen atom. After the full conversion of the N3 centres, the diamond becomes darker under CL. We hypothesize the dark core has a specific shape due to the post-growth diffusion of the hydrogen.
Journal of Mining Institute * not sure if in english?, Vol. 239, 5, pp. 492-496.
Russia
diamond crystallography
Abstract: The article presents the results of a study of the internal structure of highly elongated diamond crystals from placers in the Krasnovishersky district of the Urals. Very elongated crystals are found within diamond-bearing placer with unrevealed primary sources. Determining the conditions of such crystals formation can help one to determine the primary deposits type. There are three hypotheses for the formation of the elongated shape of such crystals: 1) crystals initially elongated along the <100> (strongly distorted octahedra); 2) individual crystals of columnar aggregates; 3) elongated crystals fragments. To study the internal structure, we selected three most elongated individuals of the 155 crystals samples. The study of the internal structure of selected crystals with the usage of photoluminescent (PL) tomography, cathodoluminescence (CL), and optical microscopy has shown that these samples are fragments of larger single crystals. CL imaging allowed to determine slip lines within the crystal's volume. The recorded PL spectra show the 912, 946, and 986 nm peaks, which are characteristic of crystals with plastic deformation. The revealed features are indicators of plastic deformation accompanying the destruction of the crystals. The significant dissolution following the destruction of the crystals led to the rounding of the vertices and edges of their fragments. Apparently, most of the very elongated crystals from placers with unknown sources are also highly dissolved isometric crystal fragments. The obtained results have shown that the deformation and dissolution of diamond crystals are related events characteristic of diamonds from hitherto undetected, but highly productive primary deposits.
Abstract: Before cutting and polishing, diamonds have highly variable surface features rarely, if ever, seen by the jewelry wearer. These features can tell an interesting story of diamond’s geological history deep within Earth-both in the mantle rocks where diamonds grew and during their subsequent volcanic transport. Our previous column showed that volcanic eruptions of kimberlite are how diamonds make their way from depth in the mantle to Earth’s surface. But this violent process does not leave the rough diamond unscathed. These early histories are rarely considered once the diamond has been faceted and set into jewelry, but they raise interesting and geologically important questions: Why do rough diamonds look so different from each other, and what might this tell us about their geological history? What effect does the kimberlite magma have on the diamond cargo? How can we see through this later stage of the diamond’s history to its millions and billions of years of mantle storage?
The American Mineralogist, in press available 59p. Pdf
South America, Guyana
diamond crystallography
Abstract: Diamonds have long been mined from alluvial terrace deposits within the rainforest of Guyana, South America. No primary kimberlite deposits have been discovered in Guyana, nor has there been previous studies on the mineralogy and origin of the diamonds. Paleoproterozoic terranes in Guyana are prospective to diamond occurrences because the most productive deposits are associated spatially with the eastern escarpment of the Paleoproterozoic Roraima Supergroup. Geographic proximity suggests that the diamonds are detrital grains eroding from the <1.98 Ga conglomerates, metamorphosed to zeolite and greenschist facies. The provenance and paragenesis of the alluvial diamonds are described using a suite of placer diamonds from different locations across the Guiana Shield. Guyanese diamonds are typically small, and those in our collection range from 0.3 to 2.7 mm in diameter; octahedral and dodecahedral, with lesser cubic and minor macle forms. The diamonds are further subdivided into those with abraded and non-abraded surfaces. Abraded diamonds show various colors in cathodoluminescence whereas most non-abraded diamonds appear blue. In all populations, diamonds are predominantly colorless, with lesser brown to yellow and very rare white. Diamonds are predominantly Type IaAB and preserve moderate nitrogen aggregation and total nitrogen concentrations ranging from trace to ~1971 ppm. The kinetics of nitrogen aggregation indicate mantle-derived residence temperatures of 1124 ± 100 ºC, assuming residence times of 1.3 Ga and 2.6 Ga for abraded and non-abraded diamonds respectively. The diamonds are largely sourced from the peridotitic to eclogitic lithospheric upper mantle based on both ?13C values of -5.82 ± 2.45‰ (VPDB-LSVEC) and inclusion suites predominantly comprised of forsterite, enstatite, Cr-pyrope, chromite, rutile, clinopyroxene, coesite, and almandine garnet. Detrital, accessory minerals are non-kimberlitic. Detrital zircon geochronology indicates diamondiferous deposits are predominantly sourced from Paleoproterozoic rocks of 2079 ± 88 Ma.
Abstract: Diamond is a material of immense technological importance and an ancient signifier for wealth and societal status. In geology, diamond forms as part of the deep carbon cycle and typically displays a highly ordered cubic crystal structure. Impact diamonds, however, often exhibit structural disorder in the form of complex combinations of cubic and hexagonal stacking motifs. The structural characterization of such diamonds remains a challenge. Here, impact diamonds from the Popigai crater were characterized with a range of techniques. Using the MCDIFFaX approach for analysing X-ray diffraction data, hexagonality indices up to 40% were found. The effects of increasing amounts of hexagonal stacking on the Raman spectra of diamond were investigated computationally and found to be in excellent agreement with trends in the experimental spectra. Electron microscopy revealed nanoscale twinning within the cubic diamond structure. Our analyses lead us to propose a systematic protocol for assigning specific hexagonality attributes to the mineral designated as lonsdaleite among natural and synthetic samples.
Contributions to Mineralogy and Petrology, Vol. 175, 98 10.1007/s00410-020-01741-w 11p. Pdf
Russia, Yakutia
diamond crystallography
Abstract: The 35 paired diamond intergrowths of rounded colorless transparent and gray opaque crystals from the placers of northeastern Siberian Platform were investigated. Mineral inclusions (KFsp, Coe, E-Grt, Po) detected in studied samples belong to eclogitic paragenesis. The majority of studied samples have uniform ranges of nitrogen content (1126-1982 at. ppm) and carbon isotope composition (??16.8 to ??23.2 ‰). These characteristics pointing towards subducted material are possible sources for their genesis. Two samples consist of a gray opaque crystal with the subduction-related characteristics (?13C ca. ??21‰ and N ca. 1300 at. ppm) and a transparent crystal with low nitrogen content (412 and 29 at. ppm) and a heavy carbon isotopic composition (?13C ??4.2 and ??4.6‰) common for primary mantle range. The higher degree of nitrogen aggregation in the crystals with mantle-like characteristics testifies their longer storage in the mantle conditions. These samples reflect multistage diamond growth history and directly indicate the mixing of mantle and subduction carbon sources at the basement of subcontinental lithospheric mantle of northeastern Siberian Platform.
Abstract: A freely moving diamond trapped inside another diamond was discovered in Siberia by Alrosa in 2019. The unusual diamond, nicknamed the “Matryoshka” after the traditional Russian nesting dolls, attracted widespread interest in how this feature formed.
Abstract: The detailed phase composition and characteristics of diamond crystals grown in the metal-silicate-H2O-C system at 5.5 GPa and 1385 °C are reported in this paper. The conversion efficiency of the graphite-to-diamond in the metal-silicate-C system is lower than that in the metal-C system, which significantly decreases the growth rate of crystal. As the Mg2Si3O8•5H2O content increases to 1.5 wt%, growth pits and {110} related features of trigonal pyramids, skeletal structure, rhombic dodecahedron, and {110} dendrites exhibit in sequence. Simultaneously, the content of graphite and metal inclusions inside the crystal increases. These systematic changes are accompanied by the appearance of Csingle bondH, Csingle bondO, and Cdouble bondO bonds and a decrease of nitrogen content from ?210 ppm to ?60 ppm. It is speculated that H2O will further decompose and bond with carbon atoms and finally enter the diamond structure. The formation of Csingle bondH and Cdouble bondO bonds will terminate the extension of the three-dimensional network of Csingle bondC bonds. These defects will accumulate along the [111] direction and form {110} related characteristics. These chemical bonds also compete with the nitrogen in the system during entering into the diamond lattice. Our experimental model may provide implications for the morphology and formation environment of natural diamonds.
Crystallography Reports, Vol. 66, 6, pp. 934-939. 10.1134/S1063774521060298
Cosmos
Crystallography
Abstract: The Mars exploration rovers have used various remote-sensing instruments over the last two and a half decades. The Chemistry and Camera tool uses laser-induced breakdown spectroscopy to obtain semi-quantitative elemental abundances. The SuperCam instrument is a response to the requirement for remote mineralogy and is also adapted for Raman spectroscopy studies. Both analyzers contain pulsed laser units with Nd:YAG rods and Pockels cells with crystals of rubidium titanyl phosphate, potassium titanyl phosphate and lithium triborate. The specific features of their structure, chemistry, and crystal growth are discussed.
