sil·​i·​ca | \ ˈsi-li-kə How to pronounce silica (audio) \

Definition of silica

: the dioxide of silicon SiO2 occurring in crystalline, amorphous, and impure forms (as in quartz, opal, and sand respectively)

Examples of silica in a Sentence

Recent Examples on the Web Its high reactivity with oxygen urges it to form compounds, including silicates (like clay) and silica (like quartz). David Lumb, Popular Mechanics, "109 Ways Silicon Completely Rules Every Part of Your Life," 9 Dec. 2020 Basalt has higher amounts of silica and iron than the kinds of rock found at the Canadian glacier, which means that all that glacial grinding at Kötlujökull should produce more hydrogen gas. Kate Baggaley, Popular Science, "Glacier-dwelling bacteria thrive on chemical energy derived from rocks and water," 30 Dec. 2020 Glass, meanwhile, is formed of the compound silica, also known as silicon dioxide. David Lumb, Popular Mechanics, "109 Ways Silicon Completely Rules Every Part of Your Life," 9 Dec. 2020 That ginseng improves energy, say, or that ginger alleviates nausea, or that horsetail, which contains silica, might help hair to grow? Amanda Fortini, New York Times, "Revisiting an Ancient Theory of Herbalism," 12 Nov. 2020 In addition to visual impacts, the crystalline silica released when rock is pulverized poses a serious threat to human health when inhaled. Brian Maffly, The Salt Lake Tribune, "Can gravel mining and world-class cherry orchards coexist in Utah?," 4 Oct. 2020 The new design involves a kilometer of silica fiber that’s doped with a neodymium isotope and then kept in a cylindrical container of solution. Caroline Delbert, Popular Mechanics, "Scientists Built the Best Solar Laser Ever," 23 Sep. 2020 Eventually, the silicon carbide turned into diamonds and silica. Chris Ciaccia, Fox News, "Alien planets in deep space could be made of diamonds, researchers suggest," 20 Sep. 2020 Some of these exoplanets containing more carbon could actually be composed of diamonds and silica if water is present. Ashley Strickland, CNN, "Carbon-rich planets made of diamonds may exist beyond our solar system, study says," 14 Sep. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'silica.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of silica

circa 1801, in the meaning defined above

History and Etymology for silica

New Latin, from Latin silic-, silex hard stone, flint

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Time Traveler for silica

Time Traveler

The first known use of silica was circa 1801

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Statistics for silica

Last Updated

24 Jan 2021

Cite this Entry

“Silica.” Dictionary, Merriam-Webster, Accessed 26 Jan. 2021.

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How to pronounce silica (audio)

English Language Learners Definition of silica

: a chemical that contains silicon, that is found in sand and quartz, and that is used to make glass


sil·​i·​ca | \ ˈsil-i-kə How to pronounce silica (audio) \

Medical Definition of silica

: the dioxide of silicon SiO2 that is used as an ingredient of simethicone and that occurs naturally in crystalline, amorphous, and impure forms (as in quartz, opal, and sand respectively)

called also silicon dioxide

More from Merriam-Webster on silica

Nglish: Translation of silica for Spanish Speakers Encyclopedia article about silica

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