any of a number of very soft, monoclinic, hydrous silicate minerals resulting usually from alterations of mica and occurring in tiny, leafy scales that expand greatly when heated: used for insulation, water adsorption, etc.
< L vermiculus, dim. of vermis, worm + -ite
See vermiculite in American Heritage Dictionary 4
Any of a group of micaceous hydrated silicate minerals related to the chlorites and used in heat-expanded form as insulation and as a planting medium.
Origin: Latin vermiculus
Origin: , diminutive of vermis, worm; see vermicular