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

Home Depot, Lowe’s and Costco are still selling crystalline silica products as of June 2026. —David Michaels, Fortune, 21 June 2026

Home Depot, Lowe’s and Costco are still selling crystalline silica products as of June 2026. —David Michaels, The Conversation, 18 June 2026

In fact, this full-coverage, Best of Beauty-winning formula targets oil at its source with lightweight silica particles that absorb oil and diffuse light to keep shine in check for a full day. —Jailynn Taylor, Allure, 13 June 2026

Calcium hydroxide forms and immediately reacts with the silica network. —Aamir Khollam, Interesting Engineering, 12 June 2026

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