Silicate and Oxide Inclusions in Diamonds from the Orapa Mine, Botswana.

Gurney, J.J.; Harris, Jeffrey W.; Rickard, R. S.

doi:10.1016/b978-0-444-42274-3.50007-x

Cited by 51 publications

(22 citation statements)

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“…Olivine inclusions in diamonds have a bimodal distribution in terms of Mg/(Mg + Fe) at localities such Roberts Victor, Orapa and Premier mines (Gurney et al, 1984a(Gurney et al, ,b, 1985 where, as at Sloan, the more Fe-rich olivines are associated with diamonds of a lherzolitic, not harzburgitic population.…”

Section: Comparison Of Kelsey Lake and Sloan-george Creek Diamond Incmentioning

confidence: 96%

“…Mineral compositions are presented in Tables 2-5. Compositional data for minerals included in diamonds from other kimberlites and alluvial occurrences shown in the figures are from Sobolev (1977Sobolev ( , 1984, Sobolev et al (1976Sobolev et al ( , 1978Sobolev et al ( , 1984Sobolev et al ( , 1989Sobolev et al ( , 1997Sobolev et al ( , 1998aSobolev et al ( ,b, 1999Sobolev et al ( , 2000, Gurney et al (1984aGurney et al ( ,b, 1985Gurney et al ( , 1994, Jaques et al (1989), Otter (1990), Wilding (1990), Chinn (1995), Davies et al (1999), Richardson et al (1999), Viljoen et al (1999), Kaminsky et al (2000), Phillips et al (2004), Pokhilenko et al (2004), Stachel et al (2003Stachel et al ( , 2004, Schulze et al (2004Schulze et al ( , 2006, Geologic Survey of Canada (1989), J. J. Gurney, personal communication (1985), K. S. Viljoen, personal communication (2005).…”

Section: Techniquesmentioning

confidence: 97%

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Mineral inclusions in diamonds from the Kelsey Lake Mine, Colorado, USA: Depleted Archean mantle beneath the Proterozoic Yavapai province

Schulze

Coopersmith²,

Harte

et al. 2008

Geochimica et Cosmochimica Acta

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Section: Comparison Of Kelsey Lake and Sloan-george Creek Diamond Incmentioning

confidence: 96%

Section: Techniquesmentioning

confidence: 97%

Mineral inclusions in diamonds from the Kelsey Lake Mine, Colorado, USA: Depleted Archean mantle beneath the Proterozoic Yavapai province

Schulze

Coopersmith²,

Harte

et al. 2008

Geochimica et Cosmochimica Acta

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“…This estimate places the Guaniamo deposits among a small group of diamond deposits worldwide that are strongly dominated by eclogite-derived diamond. These include the Argyle lamproite (Jaques et al 1989), the Orapa pipe (Gurney et al 1984, Deines et al 1993, the Premier mine (Gurney et al 1985) and some pipes of the Arkhangelsk region (Zakharchenko et al 1991) and the Slave Craton (Davies et al 1999).…”

Section: Discussionmentioning

confidence: 99%

Diamond From the Guaniamo Area, Venezuela

Kaminsky

Zakharchenko

Griffin

et al. 2000

The Canadian Mineralogist

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More than 5,000 diamond crystals (or fragments) from kimberlite sills and placer deposits in the Guaniamo area of Venezuela have been characterized in terms of morphology, internal structure, carbon isotopic composition, syngenetic mineral inclusions, and the abundance and aggregation state of nitrogen. Ours is the first comprehensive mineralogical study of diamond from the Guaniamo area. About 50% of the crystals are resorbed dodecahedral forms; octahedra are the next most common form. In most cases, the diamond is colorless; 55-90% show radiation-induced pigmentation. About 20% of the stones have very low N contents (Type II); the remainder belong to the transitional IaAB type, with B > A. Ninety-three mineral inclusions were extracted from 77 crystals or fragments of diamond and analyzed by electron microprobe and LAM-ICP-MS to establish their traceelement compositions and the pressures and temperatures of diamond crystallization. In all, 86% of the diamond samples contain inclusions of the eclogitic paragenesis, represented by garnet, omphacite, rutile, ilmenite, pyrrhotite, and probable coesite. Inclusions indicative of the peridotite paragenesis are pyrope, chromian spinel and olivine. One inclusion of ferroan periclase may indicate a lower-mantle origin. The ␦ 13 C of 108 diamond samples ranges from -3.2‰ to -28.7‰, but most stones have ␦ 13 C ≤10‰. We contend that in large part, the diamond in placers in the Guaniamo area was derived from the Guaniamo kimberlite sills. P-T estimates on mineral inclusions suggest that most originated near the base of the lithosphere (T 1200-1300°C); this zone may contain a substantial proportion of eclogite formed by subduction of crustal material. The very high proportion of diamond derived from an eclogitic association in the Guaniamo deposits, and several features of the mineral inclusions trapped in diamond, show striking parallels to the Argyle deposit of Australia. Both deposits occur within cratons that have experienced extensive Proterozoic tectonothermal activity.Keywords: diamond, carbon isotope, nitrogen, mineral inclusions, eclogitic association, Guaniamo, Venezuela. SOMMAIRENous avons caractérisé plus de 5,000 cristaux (ou fragments) de diamant provenant de filons-couches de kimberlite et de dépôts alluvionnaires dans la région de Guaniamo, au Vénézuela, selon leur morphologie, leur structure interne, la composition isotopique du carbone, leurs inclusions minérales syngénétiques, et l'abondance et l'état d'agrégation de l'azote. Ce travail * Publication No. 213 of the ARC National Key Centre for Geochemical Evolution and Metallogeny of Continents (GEMOC). § E-mail address: felixvkaminsky@cs.com 1348 THE CANADIAN MINERALOGIST constitue la première étude minéralogique compréhensive du diamant de la région de Guaniamo. Environ 50% des cristaux ont une forme dodécaédrique résorbée; l'octaèdre est la deuxième forme la plus courante. Dans la plupart des cas, le diamant est incolore; entre 55 et 90% des échantillons font preuve d'une pigmentation due à une i...

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“…Subcalcic Cr-rich garnets are one of the principle diamond ''indicator" minerals in the search for ''P-type" diamond deposits and are termed ''G10" garnets (Dawson & Stephens, 1975;Gurney et al, 1984). Such garnets have not equilibrated with clinopyroxene (Gurney and Switzer, 1973;Sobolev et al, 1973) and are a major host for trace elements in dunites and harzburgites (Shimizu et al, 1997).…”

Section: Introductionmentioning

confidence: 97%