jadeite


jadeite
/jay"duyt/, n.
a mineral, essentially sodium aluminum silicate, NaAlSi2O6, usually fibrous, occurring in compact masses, whitish to dark green: a form of jade.
[1860-65; JADE1 + -ITE1]

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Gem-quality silicate mineral in the pyroxene family that is one of the two forms of jade.

Jadeite (imperial jade), sodium aluminum silicate (NaAlSi2O6), may contain impurities that give it a variety of colours: white, green, red, brown, and blue. The most highly prized variety is emerald green. Jadeite occurs only in metamorphic rocks, most often in those that have been subjected to the high pressures deep below the Earth's surface. The area around the city of Mogaung in northern Myanmar has long been the main source of gem-quality jadeite.

Uncut (left) and cut jadeite

Runk/Schoenberger
Grant Heilman

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 gem-quality silicate mineral in the pyroxene family that is one of the two forms of jade (q.v.). The more prized of the two types of jade, jadeite (imperial jade) is usually found as transparent-to-opaque, compact, cryptocrystalline lenses, veins, or nodules. It may be distinguished from nephrite (mutton-fat jade), jade's other form, by its granular fracture and glassy lustre; in addition, polished surfaces often show pitting caused by varying hardness. Jadeite, sodium aluminum silicate (NaAlSi2O6), may contain a number of impurities (often calcium) that give it a variety of colours: white, emerald green, apple green, red, brown, and blue. Deep green to greenish black varieties are called chloromelanite and are coloured by iron.

      Jadeite occurs only in metamorphic rocks, most often in those that have been subjected to the high pressures deep below the Earth's surface. Jadeite is rare; its presence at the surface indicates great uplift of earlier buried regions and great amounts of erosion. The most important source is the large deposit near Tawmaw, Myanmar (Burma). Jadeite has also been found near Omi and Kotaki, Japan; in the Motagua River valley of Guatemala; in San Benito county, Calif.; Kazakhstan; and the Ural Mountains, Russia.

      For detailed physical properties of jadeite, see gemstone (table); pyroxene (table).

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Universalium. 2010.

Look at other dictionaries:

  • Jadéite — Catégorie IX : silicates[1] Jadéite brute, Myanmar …   Wikipédia en Français

  • jadéite — [ ʒadeit ] n. f. • 1873; de jade ♦ Minér. Silicate d aluminium et de sodium, variété de jade plus aisément fusible. ● jadéite nom féminin (de jade) Silicate naturel d aluminium et de sodium, de couleur verte ou blanchâtre, appartenant au groupe… …   Encyclopédie Universelle

  • Jadeite — Jade ite, n. (Min.) See {Jade}, the stone. [1913 Webster] …   The Collaborative International Dictionary of English

  • jadeite — [jād′īt΄] n. [ JAD(E) + ITE1] a translucent, usually greenish, mineral, sodium aluminum iron silicate, Na(Al,Fe)Si2O6, of the pyroxene group, found only in metamorphic rock, esp. in Myanmar: it is the most precious type of jade …   English World dictionary

  • Jadeite — This article is about the mineral. For other uses, see Jadeite (disambiguation). Jadeite Jadeite General Category …   Wikipedia

  • Jadeïte — Jade Pour les articles homonymes, voir Jade (homonymie). Jade Catégorie IX : silicates …   Wikipédia en Français

  • jadéite — (entrée créée par le supplément) (ja dé i t ) s. f. Sorte de pierre. •   Des haches de néphrite et de jadéite d une grandeur telle qu on n en a jamais rencontré dans les habitations lacustres, Journ. offic. 5 janv. 1873, p. 57, 2e col …   Dictionnaire de la Langue Française d'Émile Littré

  • jadeite — žadeitas statusas T sritis chemija apibrėžtis Mineralas. formulė NaAl[Si₂O₆] atitikmenys: angl. jadeite rus. жадеит …   Chemijos terminų aiškinamasis žodynas

  • jadeite — noun Etymology: French Date: 1865 a usually green monoclinic mineral of the pyroxene group that is a silicate of sodium and aluminum and is a jade • jaditic adjective …   New Collegiate Dictionary

  • jadeite — noun A pyroxene mineral, a sodium aluminium silicate with the chemical formula Na(Al,Fe)SiO, found in metamorphic rocks …   Wiktionary


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