Bentonite is an absorbent aluminium phyllosilicate generally impure clay consisting mostly of montmorillonite, (Na,Ca)0.33(Al,Mg)2Si4O10(OH)2·(H2O)n.
The absorbent clay was given the name bentonite by an American geologist sometime after its discovery in about 1890 - after the Benton Formation (a geological stratum, at one time Fort Benton) in eastern Wyoming's Rock Creek area.
Other modern discoveries include Montmorillonite discovered in 1847 in Montmorillon in the Vienne prefecture of France, in Poitou-Charentes, South of the Loire Valley and Pascalite discovered in about 1830 by French-Canadian fur trapper Emile Pascal atop the 8600-foot high Big Horn Mountains in Wyoming, USA.
At Nexus China Clay, processed or refined white bentonite is available in powder and in lumps form. The various grades and their applications are:
| GRADE | FORM | APPLICATIONS |
|---|---|---|
| Nexus Bent - I | powder / lumps | Oil well drilling |
| Nexus Bent - II | powder / lumps | Ceramic body composition |
| Nexus Bent - III | powder / lumps | Ceramic body composition |