Vermiculite

Searles Vermiculite

Vermiculite is a natural mineral that expands with the application of heat. The expansion process is called exfoliation and it is routinely accomplished in purpose-designed commercial furnaces. Vermiculite is formed by hydration of certain basaltic minerals.

A hydrated Magnesium Aluminum Silicate, it is lightweight, inorganic (incombustible), compressible, highly absorbent, non-reactive (yet compatible in many chemical compositions as a functional filler), may have a high cation exchange capacity (surface chemistry may be modified), and is available locally and globally.

Vermiculite is used successfulling in potting mixes.