Perlite is a naturally occurring siliceous volcanic glass lava containing combined water, falling into the category of igneous rock. The distinguishing feature which sets perlite apart from other volcanic glassed is that when heated to a suitable point in its softening range, it expands from four to twenty times its original volume. Expanded perlite can be manufactured to weigh as little as 70kg per cubic meter making it adaptable for numerous applications, for example, construction, horticulture and industrial applications.