silica

American  

[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.

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silica British  

/ 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

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silica Scientific  

/ sĭl′ĭ-kə /

1. 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: SiO ₂ .

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Etymology

Origin of silica

1795–1805; < New Latin, derivative of Latin silex silex

Compare meaning

How does silica compare to similar and commonly confused words? Explore the most common comparisons:

• silica vs. silicon

Example Sentences

In 1970, Corning Glass Works developed hair-thin silica strands capable of carrying light for miles with dramatically reduced signal loss.

From The Wall Street Journal • Apr. 24, 2026

The system uses silica glass, a common material that is resistant to changes in temperature, moisture and electromagnetic interference.

From Barron's • Feb. 18, 2026

While natural ice crystals in clouds are much larger than the silica particles used in the lab, the team hopes that understanding these small-scale effects will reveal the larger processes that create lightning.

From Science Daily • Nov. 24, 2025

Pigments made of minerals including hematite and rocks like lapis lazuli are ground into nanoparticles and suspended in silica, resembling “melted glass,” as Magaloni describes.

From Los Angeles Times • Sep. 1, 2025

The scabs look like rocks, bumpy, with a sheen like silica; or else like some kind of fungus.

From "Cat's Eye" by Margaret Atwood