Vermiculite is non-organic soil and is similar in certain ways to perlite, but there are some distinct differences. Both are lightweight, water retentive and non-toxic making them alike in that sense. One major difference lies in the fact that perlite originates from volcanic glass, whereas vermiculite contains mica, a sheet silicate mineral.

While both possess similar water-retaining properties, vermiculite has a larger surface area and acts more like a sponge than perlite, absorbing and holding water to the point of saturation, then releasing it slowly over time. It also creates a soil environment that retains water.  Vermiculite is also effective at aerating or expanding the soil.