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[sil-i-kuh] /ˈsɪl ɪ kə/
the dioxide form of silicon, SiO 2 , occurring especially 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.
Origin of silica
1795-1805; < New Latin, derivative of Latin silex silex Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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Examples from the web for silica
  • Under a high-powered microscope the silica shells of single-celled algae are revealed in all their manifold beauty.
  • Lighter materials, such as the mineral silica, rose to the surface.
  • Raw materials, including silica and plant ash, were heated inside ovoid vessels that might have been recycled beer jars.
  • Similar reflective structures made from silica are also responsible for the shimmering color found in opals.
  • Diatoms already secrete silica by exocytosis-a biological process by which cells direct secreted material outside the cell walls.
  • The chemists are not sure why silica, which is not a catalyst, appeared to help produce more polymers than expected.
  • The material contains nitrogen-rich compounds called amines grown on porous silica.
  • Yes, there's a lot of silica around, but computers currently need it and solar panels do not.
  • Radiolarians are tiny protists that live inside intricate silica shells.
  • He began with rubber and silica, then progressed to bivalves and mice.
British Dictionary definitions for silica


the dioxide of silicon, occurring naturally as quartz, cristobalite, and tridymite. It is a refractory insoluble material used in the manufacture of glass, ceramics, and abrasives
short for silica glass
Word Origin
C19: New Latin, from Latin: silex
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for silica

"hard silicon dioxide," 1801, Modern Latin, from Latin silex (genitive silicis) "flint, pebble," on model of alumina, soda.

Online Etymology Dictionary, © 2010 Douglas Harper
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silica in Medicine

silica sil·i·ca (sĭl'ĭ-kə)
A crystalline compound occurring abundantly as quartz, sand, and many other minerals and used to manufacture a variety of materials, especially glass and concrete.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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silica in Science
A chemical compound that is the main constituent of most of the Earth's rocks. Silica occurs naturally in five crystalline forms (quartz, tridymite, cristobalite, coesite, and stishovite), in a cryptocrystalline form (chalcedony), and in an amorphous form (opal). It is also the main chemical compound in sand. Silica is used to make glass, concrete, and other materials. Also called silicon dioxide. Chemical formula: SiO2.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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