2024-07-04
Vermiculite
Vermiculite is a hydrous phyllosilicate mineral which undergoes significant expansion when heated. Exfoliation (other links: A, B) occurs when the mineral is heated sufficiently; commercial furnaces can routinely produce this effect. Vermiculite forms by the weathering or hydrothermal alteration of biotite or phlogopite.[3] Large commercial vermiculite mines exist in the United States, Russia, South Africa, China, and Brazil.