vermiculite

American  

[ver-mik-yuh-lahyt] / vərˈmɪk yəˌlaɪt /

noun

1. any of a group of platy minerals, hydrous silicates of aluminum, magnesium, and iron, that expand markedly on being heated: used in the expanded state for heat insulation and as a plant growth medium.

---

vermiculite British  

/ vɜːˈmɪkjʊˌlaɪt /

noun

1. any of a group of micaceous minerals consisting mainly of hydrated silicate of magnesium, aluminium, and iron: on heating they expand and exfoliate and in this form are used in heat and sound insulation, fireproofing, and as a bedding medium for young plants

---

Etymology

Origin of vermiculite

An Americanism dating back to 1815–25; vermicul(ar) + -ite ¹

Example Sentences

Attorneys for the estates of the two victims — Joyce Walder and Thomas Wells — had argued that the railroad knew the asbestos-tainted vermiculite was dangerous but failed to act.

From Seattle Times • Apr. 22, 2024

He told jurors last week the railroad’s employees didn’t know the vermiculite was filled with hazardous microscopic asbestos fibers.

From Seattle Times • Apr. 22, 2024

They should be disposed of in decided bins, in shops or recycling centres, containing a mineral called vermiculite to reduce the risk of fires.

From BBC • Sep. 7, 2023

Each mushroom grows out of an oversize test tube packed with sand-like vermiculite bathed in liquid growth media, a mixture of acetate and inorganic nutrients including phosphorus and nitrogen.

From Science Magazine • Jun. 7, 2023

In the laboratory, male gypsy moths have attempted copulation with chips of wood, vermiculite, and other small, inanimate objects, so long as they were suitably impregnated with gyplure.

From "Silent Spring" by Rachel Carson