What is Vermiculite?

Vermiculite is the mineralogical name given to hydrated laminar magnesium-aluminum-iron silicate that resembles mica in appearance. All vermiculite ores contain a range of other minerals that were formed along with the vermiculite in the rock. Vermiculite ores from some sources have been found to contain asbestos minerals but asbestos is not intrinsic to vermiculite and only a few ore bodies have been found to contain more than tiny trace amounts. See: http://www.epa.gov/asbestos/pubs/verm.html