What is perlite and what is it used for?

Perlite is a natural volcanic rock that is processed and expanded to create a lightweight, porous material. 

Hand with a handful of perlite

Perlite is formed when obsidian, a type of volcanic rock, is rapidly heated to a high temperature, causing it to expand and form bubbles. These bubbles give perlite its characteristic lightweight and porous structure.

What is perlite used for?

Hand holding a gardening shovel from which perlite falls
Commonly used in agriculture as a soil conditioner or growing medium. It helps improve soil aeration and drainage, retaining moisture and allowing excess water to drain away. The porous nature of perlite also provides insulation, preventing the soil from overheating in hot weather.
It is generally mixed with potting soil or other growing media. The ratio of perlite to potting soil like this may vary depending on the specific needs of the plant, but a common recommendation is to use a 1:1 ratio.
It can also be used as a stand-alone substrate for hydroponic systems or as a rooting medium for cuttings.
Besides agriculture, it has several other applications. In fact, it is used in building materials such as lightweight concrete, plasters and mortars to improve insulation and fire resistance properties.
Perlite is also used in liquid and gas filtration, as well as in the production of cosmetics, personal care products and some food processing applications.

In conclusion

All in all, perlite is a versatile and widely used material in various sectors, mainly appreciated for its lightness and porosity, which offers advantages such as better drainage, insulation and ventilation.