Bentonite, Kaolin and Selected Clay Minerals (EHC 231, 2005)
1. SUMMARY 1.1 Identity, physical and chemical properties, and analytical methods . Bentonite is a rock formed of highly colloidal and plastic clays composed mainly of montmorillonite, a clay mineral of the smectite group, and is produced by in situ devitrification of volcanic ash. In addition to montmorillonite, bentonite may contain feldspar, cristobalite, and crystalline quartz.