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

Made from amorphous silica, a form of silicon dioxide found naturally in foods and the fossilized remains of microscopic organisms, the engineered nanoparticles appear to attack prostate cancer in multiple ways at once.

From Science Daily ● Jul. 9, 2026

The research team is continuing to investigate these ultrasmall core shell silica particles as a potential new class of cancer therapies capable of influencing inflammatory, immune, and metabolic pathways at the same time.

From Science Daily ● Jul. 9, 2026

Avcoat is a mix of silica fibers, phenolic microballoons, and epoxy resin that chars and erodes, removing heat away.

From Barron's ● Apr. 10, 2026

Workers at the Evonik plant were dispatched to close the gas supply valve into the factory, where the German chemical maker produces silica for toothpaste and food products.

From The Wall Street Journal ● Feb. 10, 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 Gregory, Mary Huston