kimberlite


kimberlite
/kim"beuhr luyt'/, n.
Petrol. a variety of micaceous peridotite, low in silica content and high in magnesium content, in which diamonds are formed.
[1885-90; named after KIMBERLEY, South Africa; see -ITE1]

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or blue ground

Dark, heavy, often fragmented igneous rock that may contain diamonds in the rock matrix.

Kimberlite is a mica peridotite, an ultrabasic rock type with a complex and often highly altered mineral composition. It occurs in the Kimberley district of South Africa and the Kimberley and Lake Argyle regions of Australia, as well as near Ithaca, N.Y.

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rock
also called  blue ground 

      a dark-coloured, heavy, often altered and brecciated (fragmented), intrusive igneous rock that contains the only diamonds (diamond) known to occur in the rock matrix where they originally formed. It has a porphyritic texture, with large, often rounded crystals (phenocrysts) surrounded by a fine-grained matrix (groundmass). It is a mica peridotite, and its most abundant mineral constituent is olivine. Other abundant minerals include phlogopite mica; chromium- and pyrope-rich garnet phenocrysts; chrome-bearing diopside, particularly in the African kimberlite; ilmenite; serpentine; calcite; and magnetite.

      Kimberlite occurs in the uplifted centres of continental platforms. In the Kimberley district, South Africa, it forms pipes (funnels, more or less oval in cross section, that become narrower with increasing depth) and, occasionally, dikes. Other occurrences include the dikes at Ithaca, N.Y., the Kimberley and Lake Argyle regions of Australia, and the lavas in the Iswisi Hills, Tanzania.

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Universalium. 2010.

Look at other dictionaries:

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  • kimberlite — [ kɛ̃bɛrlit ] n. f. • 1902; de Kimberley, n. d une ville sud africaine, probablt d apr. l angl. ♦ Minér. Roche éruptive dans laquelle on trouve le diamant. ● kimberlite nom féminin (de Kimberley, nom propre) Roche ultrabasique mise en place dans… …   Encyclopédie Universelle

  • kimberlite — [kim′bər līt΄] n. [< KIMBERLEY + LITE] a kind of peridotite which sometimes contains diamonds …   English World dictionary

  • kimberlite — kimberlitas statusas T sritis chemija apibrėžtis Ultrabazinė uoliena, kurios svarbiausi mineralai – divinas, piropas, ilmenitas, deimantas. atitikmenys: angl. kimberlite rus. кимберлит …   Chemijos terminų aiškinamasis žodynas

  • kimberlite — noun Etymology: Kimberley, South Africa + 1 ite Date: 1887 an agglomerate biotite peridotite that occurs in pipes especially in southern Africa and that often contains diamonds …   New Collegiate Dictionary

  • kimberlite — noun A variety of peridotite containing a high proportion of carbon dioxide; often contains diamonds …   Wiktionary

  • kimberlite — kim·ber·lì·te s.f. TS petr. roccia eruttiva della famiglia delle peridotiti, composta da olivina, pirosseni e anfiboli, che in Sud Africa costituisce la roccia madre contenente diamanti {{line}} {{/line}} DATA: 1957. ETIMO: der. di Kimberly, nome …   Dizionario italiano

  • kimberlite — pl.f. kimberliti …   Dizionario dei sinonimi e contrari

  • kimberlite — [ kɪmbəlʌɪt] noun Geology a rare, blue tinged, coarse grained intrusive igneous rock sometimes containing diamonds, found in South Africa and Siberia. Origin C19: from Kimberley, a South African city and diamond mining centre, + ite1 …   English new terms dictionary


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