This lightweight Perlite provides superb aeration and moisture retention when mixed in with other soil materials. Perlite supports root growth and retains moisture, air, and nutrients which it releases as plants grow. Also suitable for hydroponic greenhouses. Can be made very low-density as required.
Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently. So in laymen terms it is lavarock that has been popped like popcorn!