Vermiculite is a natural, colorless mineral used mostly for construction, automotive industry, and agriculture industry. It is also found in shades of yellow, gree, and brown.
Vermiculite expands with the application of heat. The expansion process is called exfoliation and it is carried out in purpose-designed commercial furnaces.
Vermiculite is generally found in carbonatites and metamorphosed magnesium rich limestone. It also occurs as an alteration product at the contact between felsic and mafic or ultramafic rocks such as pyroxenites and dunites and is also found interlayered with chlorite, biotite and phlogopite. The deposits of vermiculite may also contain a variety of other materials such as mica, quartz, and feldspar.
Large commercial vermiculite mines currently exist in Russia, South Africa, China, and Brazil. The World Map of Vermiculite Producers shows a list of the major countries that produce large quantities of the mineral. As the data in the map shows, South Africa leads the world in the production of vermiculite; in 2010, the country produced about 2.1 million metric tonnes of the mineral. The second-largest producer of vermiculite is China with an annual production of 1.3 million metric tonnes.
Other countries producing significant amounts of vermiculite include the United States, Russia, Australia, Brazil, Zimbabwe, and Japan.
The largest vermiculite mining operation in the world is located in the Phalabowra district of the Republic of South Africa.
Processed vermiculite is very useful and is used for the production of anti-drumming coatings, condensation control paints, high performance gaskets and seals and for upgrading the fire resistance of organic foams and other polymer based systems.
Major Vermiculite Producers of the World-2010
| Country | Production in Thousand Metric Tonnes |
| South Africa | 210 |
| China | 130 |
| United States | 100 |
| Russia | 25 |
| Australia | 15 |
| Brazil | 15 |
| Zimbabwe | 5 |
| Other Countries | 26 |
