silica

American  

[sil-i-kuh] / ˈsɪl ɪ kə /

noun

• silicas
  plural

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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Other Word Forms

Noun Inflected Forms

• silicas
  plural

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

See Examples For:

silica silicas

Diatoms, sea sponges, and certain plants use biological molecules and organic scaffolds to collect dissolved silicon and build complex silica structures under relatively mild conditions.

From Science Daily ● Sep. 19, 2026

She plucks them, then buries them in silica sand for up to two weeks to drain any moisture.

From Los Angeles Times ● Sep. 2, 2026

The answer is silica, a material that is 20 times more toxic than coal.

From Barron's ● Aug. 21, 2026

The affected workers identified in the study reported 16 to 25 years of silica dust exposure while on the job.

From Los Angeles Times ● Aug. 12, 2026

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

Studies of water and ice in hydrophilic and hydrophobic mesoporous silicas: pore characterisation and phase transformations.

From Nature ● Nov. 7, 2017

Steel, the strongest of all forms of iron, is an alloy of iron and carbon, and for various purposes these are further mixed with nickel and silicas.

From Checking the Waste A Study in Conservation by Mary Huston Gregory