smectite
/ˈsmɛktʌɪt
/noun [mass noun]
A clay mineral (e.g. bentonite) which undergoes reversible expansion on absorbing water.The clay mineral smectite, with physical properties that make it unsuitable as a soil if it is wet, is only found in major amounts in covered stadiums....
- Common clays are usually mixtures of clay minerals such as illite, smectite, and kaolinite, together with fine silica and other minor constituents.
- The clay is composed of illite and kaolinite, with minor amounts of chlorite and smectite.
Origin
Early 19th century: from Greek smēktis 'fuller's earth' + -ite1.