silica

[sil-i-kuh] /ˈsɪl ɪ kə/
noun
1.
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
1795-1805; < Neo-Latin, derivative of Latin silex silex
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

silica

/ˈsɪlɪkə/
noun
1.
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
2.
short for silica glass
Word Origin
C19: New Latin, from Latin: silex
Word Origin and History for silica
n.

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

silica in Medicine

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

silica in Science
silica
  (sĭl'ĭ-kə)   
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.
Encyclopedia Article for silica

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.

Learn more about silica with a free trial on Britannica.com