Vermiculite comprises a group of hydrated, laminar magnesium-aluminum-iron silicate minerals resembling mica. They are secondary minerals, typically altered biotite, iron-rich phlogopite or other micas or clay-like minerals that are themselves sometimes alteration products of amphibole, chlorite, olivine and pyroxene. Vermiculite deposits are associated with volcanic ultramafic rocks rich in magnesium silicate minerals, and flakes of the mineral range in color from black to shades of brown and yellow. The crystal structure of vermiculite contains water molecules, a property that is critical to its processing for common uses.
|Title||Mineral resource of the month: Vermiculite|
|Authors||Arnold O. Tanner|
|Publication Subtype||Journal Article|
|Record Source||USGS Publications Warehouse|
|USGS Organization||National Minerals Information Center|