Alternate Names: Atapulgite, Palygorskite, fullers earth
A very fine highly water absorbent non-swelling clay material that imparts suspension, thixotropy and binding properties to bodies and suspensions. It is found in compact blocks in sedimentary rocks and looks like soil. It feels somewhat greasy smooth and the dried material is light in weight.
Unlike smectites and montmorillonites, attapulgites do not have a flat particle shape, they have rod-shaped particles. Particles are electrolytically charged, this enables them to function as shear-thinning thickeners and suspension agents by forming a dispersing thixotropic lattice by a non-swelling mechanism.
The high degree of refining plus the dispersant adsorbed on the product determine the self-dispersing characteristics. Attapulgite deposits are found in Florida (Active Minerals, a notable manufacturer, has products that include Acti-gel, Min-u-gel & Forigel; these differ in the amount refining).
One popular use of this material is heat-treating granules to improve liquid absorption and hardness for cat litter. The Swiss-cheese-like micro-structure gives them extraordinary capacity to absorb liquids.
Sorptive Mineral Institute for producers of absorbent clay mineral products
Acti-Gel 208 Information page
Attapulgite information page at ActiveMinerals.com
The unique properties of Acti-gel
Palygorskite at Wikipedia
Generic materials are those with no brand name. Normally they are theoretical, the chemistry portrays what a specimen would be if it had no contamination. Generic materials are helpful in educational situations where students need to study material theory (later they graduate to dealing with real world materials). They are also helpful where the chemistry of an actual material is not known. Often the accuracy of calculations is sufficient using generic materials.