What is Vermiculite? Vermiculite is a hydrous phyllosilicate mineral which undergoes significant expansion when heated. Exfoliation occurs when the mineral is heated sufficiently, and commercial furnaces can routinely produce this effect. Vermiculite forms by the weathering or hydrothermal alteration of biotite or phlogopite. Advantages: Disadvantages: Has minimum nutritional value Itโ€™s a nonrenewable resource. Hence weContinue reading “Vermiculite”