mineral wool

American  

noun

1. a woollike material for heat and sound insulation, made by blowing steam or air through molten slag or rock.

---

mineral wool British  

noun

1. Also called: rock wool.  a fibrous material made by blowing steam or air through molten slag and used for packing and insulation

---

Etymology

Origin of mineral wool

First recorded in 1880–85

Example Sentences

Common insulation materials include fibreglass, non-combustible mineral wool, foam boards and natural fibre such as wood or cork.

From BBC • Mar. 25, 2026

The angled roof is made out of a reflective, resin-coated metal and sits atop 9 inches of mineral wool insulation, which helps preserve the building’s interior temperatures and buffer external noise.

From Los Angeles Times • Sep. 19, 2023

From her front yard, Keisha Brown can see the unsightly berms of mineral wool, a byproduct of the coking process.

From Washington Post • Apr. 24, 2019

Modern materials, such as sheet metal, mineral wool and glass brick, allow the architects to design efficient "filter walls."

From Time Magazine Archive

This or the mineral wool packing will prevent the premature melting of snow from the internal heat.

From The House that Jill Built after Jack's had proved a failure by Gardner, E. C. (Eugene Clarence)