smectite

/ˈsmɛktaɪt/
noun
  1. A group of clay minerals that can absorb water and expand, often used in drilling fluids, cat litter, and as a soil additive.
    • Drilling companies add smectite to their fluids to help lubricate the drill bit.
    • The soil in this region contains smectite, which makes it swell when it rains.
    • Smectite clays are commonly used in cat litter because they clump together when wet.
Synonyms