Perlite
A volcanic glass that puffs up like popcorn when heated, giving light, fire-resistant insulation, plasters, filter aids and potting mixes.
Industrial minerals · No. 70
- Not on a critical list
- HHI 2,254 · moderately concentrated
Heat perlite quickly and it pops like popcorn, swelling up to 20 times into a light, white granule.
Chart: Illustration: Perlite
Where it comes from
Chart: Map of where it comes from
Perlite is a volcanic glass holding a few per cent of water. It is quarried, crushed and dried, then flash-heated so the water turns to steam and the grains expand up to 20 times.
Three things to know
- China, Turkey, Greece and the United States produced 92% of world perlite in 2025.
- Building construction products took 45% of US expanded perlite in 2025, with horticulture and filter aids at 15% each.
- Greece holds about 180 Mt of listed reserves, the most of any country, and supplied 94% of US imports in 2021-24.
The journey
- 1 Volcanic glassRhyolitic glass holding 2-5% water
- 2 Open pitQuarried from surface deposits
- 3 Processed crudeCrushed, dried and sized
- 4 ShipmentSent to expansion plants near markets
- 5 ExpansionFlash-heated until it puffs up
- 6 End usesPlaster, insulation board, filters, potting mixes