silica

noun

sil·​i·​ca ˈsi-li-kə 

: 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

While that hole likely formed in a single major explosive event, the newest thermal feature appears to have formed by multiple small events that initially threw rocks but later threw silica mud a short distance, creating a small pit that became filled with silica-rich water. —Julia Jacobo, ABC News, 16 July 2025

Local employees worked for three divisions: Compensation Analysis and Support, which provided scientific support for claims involving Department of Energy workers with cancer caused by exposure to radiation, beryllium and silica. —Patricia Gallagher Newberry, The Enquirer, 2 July 2025

The latest proof of concept experiment builds on earlier work by Wordsworth’s team, which showed that silica aerogels could replicate Earth’s greenhouse effect to support life in cold, low-pressure environments. —Sharmila Kuthunur, Space.com, 20 July 2025

Microscope image of silica droplets, or microspherules, found in the rock. —Monica Cull, Discover Magazine, 10 July 2025

Word History

Etymology

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

First Known Use

circa 1801, in the meaning defined above

Phrases Containing silica

• silica gel
• vitreous silica

Rhymes for silica

• basilica

Kids Definition

silica

noun

sil·​i·​ca ˈsil-i-kə 

: a compound that consists of the dioxide of silicon and occurs in various forms (as in quartz, opal, and sand)

Medical Definition

silica

noun

sil·​i·​ca ˈsil-i-kə 

: 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