topaz

topazine /toh"peuh zeen', -zin/, adj.
/toh"paz/, n.
1. a mineral, a fluosilicate of aluminum, usually occurring in prismatic orthorhombic crystals of various colors, and used as a gem.
2. citrine (def. 2).
3. either of two South American hummingbirds, Topaza pella or T. pyra, having chiefly red and crimson plumage and a yellowish-green throat with a topaz sheen.
[1225-75; < L topazus < Gk tópazos; r. ME topace < OF < L, as above]

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Aluminum silicate mineral, Al2SiO4(F,OH)2, that is valued as a gemstone.

It is formed by fluorine-bearing vapours given off during the last stages of the crystallization of igneous rocks. Pure topaz may be colourless and, when brilliant-cut, has been mistaken for diamond. It may also be various shades of yellow, blue, or brown. Imperial topaz, with vivid reddish orange colour, from Minas Gerais, Braz., is very highly valued.

Topaz from Minas Gerais state, Brazil

Lee Boltin

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 silicate mineral that is valued as a gemstone. It is believed that the topaz of modern mineralogists was unknown to the ancients and that the stone called topazos was the mineral chrysolite or peridot. The “topaz” in the Old Testament also may have been chrysolite.

      Topaz is an aluminum silicate containing fluorine and has a chemical formula of Al2(F,OH)2SiO4. It is formed by fluorine-bearing vapours given off during the last stages of the crystallization of igneous rocks. It typically occurs in cavities in rhyolites and granite, in pegmatite dikes, and in high-temperature veins. Often associated with cassiterite, topaz may be useful to indicate the presence of that tin ore.

      The finest British topaz is found in the Cairngorm Mountains in the Central Highlands, especially at Ben a Buird, Scot. The famous topaz rock of the Schneckenstein, in Germany, yields pale yellow crystals that were formerly cut for jewelry. Fine topaz occurs at several localities in the Urals and in Siberia, Russia, and beautiful crystals come from Takayama and Tanokamiyama in Japan. Brazil is a famous locality, the well-known sherry-yellow crystals coming from Ouro Preto, Minas Gerais, where they occur in a kaolinitic matrix. In the United States fine topaz has been worked near Pikes Peak, Colo., and in San Diego county, Calif. Common topaz occurs in coarse crystals at many localities. For detailed physical properties, see silicate mineral (table).

      Pure topaz may be colourless and, when brilliant-cut, has been mistaken for diamond. It may also be coloured various shades of yellow, blue, or brown; the colour in many cases is unstable, and the brown topazes of Siberia are particularly liable to be bleached by sunlight. In 1750 a Parisian jeweler discovered that the yellow Brazilian topaz becomes pink on exposure to a moderate heat, and this treatment has since been extensively applied, so that nearly all the pink topaz occurring in jewelry has been heat-treated. Such “burnt topaz” is often known as Brazilian ruby, as is the very rare, natural red topaz. Cut topazes of large size are known, and it is said that the great “Braganza diamond” of Portugal is probably a topaz.

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Universalium. 2010.

Look at other dictionaries:

  • Topaz — Herkunft Tschechien, Prag 1984 Art Malus domestica Kreuzung aus Rubin x Vanda, 1984 Liste der Apfelsorten Topaz ist eine noch relativ neue Apfelsort …   Deutsch Wikipedia

  • topaz — TOPÁZ, topaze, s.n. Silicat natural de aluminiu cu fluor, cristalizat în sistemul rombic, de obicei de culoare galbenă, folosită ca piatră preţioasă. [pl. şi: topazuri] – Din fr. topaze. Trimis de romac, 13.07.2008. Sursa: DEX 98  TOPÁZ s.… …   Dicționar Român

  • Topaz — To paz, n. [OE. topas, F. topaze, L. topazos, or topazion, a kind of precious stone, Gr. to pazos, topa zion; possibly akin to Skr. tap to glow (cf. {Tepid}). According to some, the name is from Topazos, a small island in the Red Sea, where the… …   The Collaborative International Dictionary of English

  • Topaz — f English: one of the rarer examples of the class of modern female names taken from vocabulary words denoting gemstones. The topaz gets its name via French and Latin from Greek; it is probably ultimately of oriental origin. In the Middle Ages… …   First names dictionary

  • topaz — [tō′paz΄] n. [ME topace < OFr topase < L topazus < Gr topazos] 1. a light colored or colorless, very hard, orthorhombic mineral, Al2 (SiO4)(F,OH) 2, often used as a gem; hydrous aluminum silicate: see MOHS SCALE 2. any of a various… …   English World dictionary

  • tòpaz — m min. aluminijev fluorid silikat, najčešće žute boje, cijenjen kao dragulj ✧ {{001f}}grč …   Veliki rječnik hrvatskoga jezika

  • topaz — (n.) colored crystalline gem, late 13c., from O.Fr. topace (11c.), from L. topazus, from Gk. topazos, topazion, of obscure origin. Pliny says it was named for a remote island in the Red or Arabian Sea, where it was mined, but this might be folk… …   Etymology dictionary

  • topaz — s. m. 1. Cristão mestiço, no Oriente. 2.  [Antigo] Intérprete chinês …   Dicionário da Língua Portuguesa

  • topaz — tòpaz m DEFINICIJA min. aluminijev fluorid silikat, najčešće žute boje, cijenjen kao dragulj ETIMOLOGIJA grč. tópazos …   Hrvatski jezični portal

  • topaz — {{/stl 13}}{{stl 8}}rz. mnż I, D. u, Mc. topazzie {{/stl 8}}{{stl 7}} przezroczysty minerał o pięknym zabarwieniu w różnych odcieniach, stosowany jako kamień ozdobny w jubilerstwie : {{/stl 7}}{{stl 10}}Naszyjnik z topazami. <łac.> {{/stl… …   Langenscheidt Polski wyjaśnień

  • topaz — ► NOUN 1) a colourless, yellow, or pale blue precious stone. 2) a dark yellow colour. ORIGIN Greek topazos …   English terms dictionary

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