Perlite is the geological name for a natural occurring amorphous volcanic glass, which main content is amorphous SiO2 which is extracted from open mines in different regions in the world.
By sudden heating to about 1100 degrees Celsius the water trapped in the structure evaporates creating an overpressure which makes the perlite expand up to 15 to 20 times its original volume. With this a sterile white lightweight granulate (with a typical density between 60 and 100 g/l) with a lot of cavities encircled by a thin cell wall is formed.
Perlite can be used in a wide field of applications.
