Bentonite

Bentonite is a kind of clay. Bentonite usually forms from weathering of volcanic ash. It is volcanic ash mixed with water under pressure.

The different types of bentonite have different proportions of sodium, calcium or potassium. They can absorb quite a lot of water, and are used as fillers and/or lubricators in various industries. The clay is used for many practical purposes.

Bentonite Media

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  Bentonite layers from an ancient deposit of weathered volcanic ash tuff in Wyoming

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  Gray shale and bentonites (Benton Shale; Colorado Springs, Colorado)

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  2:1 clay minerals crystallographic structure made of three superimposed sheets of Tetrahedra-Octahedra-Tetrahedra (TOT layer unit), respectively

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  Detailed molecular structure of pure montmorillonite, the best known end-member of the smectite group. The interlayer space between two successive TOT layers is filled with hydrated cations (mainly Na⁺ and Ca²⁺ ions) compensating the negative electrical charges of the TOT layers and with water molecules causing the interlayer expansion.