Clay occurs as generic term for an total of hydrous silicate particles less than 4 μm (micrometres) in diameter. Clay consists of the kind of phyllosilicate minerals rich in silicon and aluminium oxides and hydroxides which include variable amounts of structural water. Clays come typically formed per chemical substance weathering of silicate-bearing rocks by carbonic acid, but a bit of come formed by hydrothermal activity. Clays come distinguished from either more little particles present within soils such as silt by their small size, flake or even superimposed shape, affinity for a water system & high plasticity index.

There are deuce-ace independent groups of clays: kaolinite-serpentine, illite, and smectite. Altogether, there are astir xxx different types of "pure" clays inside these categories, however virtually all natural clays come mixtures one different types, too when more weather-beaten minerals.

Montmorillonite, with the formula of (Na,Ca)_0.33(Al,Mg)₂Si₄O₁₀(OH)₂·northH₂O, is typically formed as a weathering product of moo silicon dioxide rocks. Montmorillonite occurs as member of the smectite class action & the major component of bentonite.

Clays sintered in fire were the foremost ceramic, & remain one of a cheapest to green groceries and virtually all widely utilized materials possibly in the present day. Bricks, cooking pots, piece, dishware, spark plug bodies, and potentially instrument like a ocarina are all processed sustaining clay. Clay is too utilized around numbers of industrial processes, like paper making, concrete production, and chemical substance filtering.

Varve (or varved clay) is clay using seeable annual shells, formed by seasonal differences around erosion & organic content. This nature and severity of dump is park inside previous glacial streams, lakes, and wells throughout from either a ice age.

Quick clay is a unique type of marine clay, forearm to the glaciated terrains of Norway, Canada, and Sweden. These are the extremely sensitive clay, prone to liquefaction which has been involved around many fatal landslides.