The article discusses the latest developments in the global vermiculite industry as of June 2011. It defines vermiculite as a hydrated mica. It cites that the two biggest global producers of vermiculite are Rio Tinto and Samrec Vermiculite Ltd., a subsidiary of Imerys Industrial Minerals. In North America, the leading producers are Virginia Vermiculite and WR Grace & Co. Vermiculite is mainly used in the horticulture and fire protection industries.