volcanic glass

noun

: natural glass produced by the cooling of molten lava too rapidly to permit crystallization

Examples of volcanic glass in a Sentence

Recent Examples on the Web

The United States Geological Survey said fallout had created hazardous conditions in downwind areas, with one resident reporting more than an inch of tephra — a mix of magma, rock and volcanic glass — on the roads of a golf course subdivision. —Marc Ramirez, USA Today, 10 Mar. 2026

Perlite is a lightweight, porous volcanic glass used to improve aeration and drainage in soil and other plant mixes. —Michele Laufik, Martha Stewart, 10 Feb. 2026

The most recent eruption included threats of high levels of volcanic gas and Pele's hair, the term for strands of volcanic glass produced by lava fountaining activity. —Julia Jacobo, ABC News, 8 Dec. 2025

Because water has been found in lunar rock before, embedded in crystals of volcanic glass or mineral grains, lasering promising boulders may prove important. —Elizabeth Howell, Space.com, 24 Nov. 2025

Word History

First Known Use

1780, in the meaning defined above

Rhymes for volcanic glass

• bermudagrass
• alas
• amass
• bromegrass
• bypass
• chagas
• crabgrass
• crevasse
• eelgrass
• eyeglass
• groundmass
• harass