silica

silica
/sil"i keuh/, n.
the dioxide form of silicon, SiO2, occurring esp. as quartz sand, flint, and agate: used usually in the form of its prepared white powder chiefly in the manufacture of glass, water glass, ceramics, and abrasives. Also called silicon dioxide.
[1795-1805; < NL, deriv. of L silex SILEX]

* * *

also called  Silicon Dioxide,  

      compound of the two most abundant elements in the Earth's crust, silicon and oxygen, SiO2. The mass of the Earth's crust is 59 percent silica, the main constituent of more than 95 percent of the known rocks. Silica has three main crystalline varieties: quartz (by far the most abundant), tridymite, and cristobalite. Other varieties include coesite, keatite, and lechatelierite. Silica sand is used in buildings and roads in the form of portland cement, concrete, and mortar, as well as sandstone. Silica also is used in grinding and polishing glass and stone; in foundry molds; in the manufacture of glass, ceramics, silicon carbide, ferrosilicon, and silicones; as a refractory material; and as gemstones.

* * *


Universalium. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Silica — (Village) Administration Pays …   Wikipédia en Français

  • silică — SILÍCĂ, silice, s.f. Material refractar compus mai ales din bioxid de siliciu; cărămidă refractară silicioasă. – Din silice. Trimis de LauraGellner, 13.09.2007. Sursa: DEX 98  SILÍCĂ s. (constr.) dinas. (silică este o cărămidă refractară… …   Dicționar Român

  • Silica — Sil i*ca, n. [NL., from L. silex, silics, a flint.] (Chem.) Silicon dioxide, SiO?. It constitutes ordinary quartz (also opal and tridymite), and is artifically prepared as a very fine, white, tasteless, inodorous powder. [1913 Webster] …   The Collaborative International Dictionary of English

  • şilica — şílica! interj. (reg.; repetat) cuvânt cu care se cheamă raţele; mani!, uti!. Trimis de blaurb, 08.02.2007. Sursa: DAR …   Dicționar Român

  • silica — hard silicon dioxide, 1801, Modern Latin, from L. silex (gen. silicis) flint, pebble, on model of alumina, soda …   Etymology dictionary

  • sílica — s. f. 1. Substância branca e sólida chamada também óxido de silício. 2. Síliqua …   Dicionário da Língua Portuguesa

  • šilica — šȉlica ž DEFINICIJA lokal., v. krojačica ETIMOLOGIJA vidi šiti …   Hrvatski jezični portal

  • silica — ► NOUN ▪ silicon dioxide, a hard, unreactive, colourless compound which occurs as quartz and in sandstone and many other rocks. DERIVATIVES siliceous adjective. ORIGIN from Latin silex flint , on the pattern of words such as alumina …   English terms dictionary

  • silica — [sil′i kə] n. [ModL < L silex, flint: see SILEX] a glassy, very hard mineral, silicon dioxide, SiO2, found in a variety of forms, as in quartz, opal, chalcedony, sand, or chert …   English World dictionary

  • Silica — The chief component of sand and a substance responsible for lung disease and cancer. Crystalline silica of respirable size is primarily quartz dust occurring in industrial and occupational settings in the form of fine, breathable particles.… …   Medical dictionary

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”