Welcome to Imerys Performance Minerals


What is perlite?

Perlite rock

Perlite is a generic term for naturally occurring siliceous rock, which contains water that expands into steam to produce a foamed structure. Perlite is distinguished from other volcanic glasses in that when heated to a suitable point, it expands from four to twenty times its original volume. This expansion is due to the presence of two to six percent water in the crude perlite rock. The rock pops like popcorn creating tiny bubbles which account for the amazing light weight and other exceptional physical properties of expanded perlite.


Perlite, or volcanic glass, is formed when lava in the form of molten rock spews out of a volcano, and cools in a rapid manner. During cooling water is trapped within the rock and the lava forms into a glass-like structure.

Physical properties

SEM photograph Perlite
  • Lightweight 
  • Excellent thermal and acoustic insulating properties 
  • Elasticity
  • Fire resistance
  • Wide range of particle sizes
  • Construction
  • Filtration
  • Paints & Coatings
  • Personal Care
  • Horticulture
  • Construction

    Used in the construction industry, perlite is a good thermo-acoustic insulator for cavity walls and a valuable, low density fire retardant additive, ideal for meeting current trends towards lightweight building materials and concrete.

    Perlite for construction
  • Filtration

    Natural perlites are ideal solutions for filtering of fruit juices and wine in particular the difficult to filter musts from thermo-vinification.

    Wine filtration
  • Paints & Coatings

    • In dry mixes and ready-to-use plasters, perlite is an excellent additive for lightweighting.
    • In paints, perlite is the most efficient matting agent; and in varnishes it provides matting and transparency.
  • Personal Care

    The careful processing of perlite results in soft, fine particles suitable for use in a variety of personal care products where high purity, gentle abrasion, high absorption and matting effect are desired. Used in scrub applications, perlite is an excellent eco-friendly alternative to polymer-based microbeads.

    Learn more
    Woman washing face with scrub
  • Horticulture

    In horticulture, raw perlite is an environment-friendly soil amendment in growing substrates, where it improves plant growth as well as resistance to insects, disease and environmental stress.

For markets other than Personal Care, please visit Imerys Filtration.