Vermiculite 3 November, 2023 3:34 pm « Back to Glossary Index A group of micaceous minerals, all hydrated silicates, varyingwidely in composition; (Mg,Fe,Al)3(AlSi)4O10(OH)2- 4H2O. When heated above 302°F (150°C), vermiculite exfoliates and increases greatly in volume Read More