depending on the end use. Gel-grade, dry-processed attapulgites are used in a very wide range of applications for suspension, reinforcement, and binding properties. Paints, sealants, adhesives, tape-joint compound, catalysts, suspension fertilizers, wild-fire suppressants, foundry coatings, animal feed suspensions, and molecular sieve binders are just a few uses of dry-process attapulgite. 7% - 10% attapulgite clay mixed with the eutectic salt, sodium sulfate decahydrate (mirabilite or Glauber's salt), keeps anhydrous crystals suspended in the solution, where they hydrate during phase transition and hence contribute to the heat absorbed and released when Glaubers salt is used for heat storage. Stabilization of nanopalygorskite suspensions was improved using mechanical dispersion (magnetic stirring, high-speed shearing and ultrasonication) and polyelectrolytes (carboxymethyl cellulose, alginate, sodium polyphosphate, and poly(sodium acrylate)) at different pH. Surface energy and nanoroughness were studied in a palygorskite sample. Medical use Attapulgite is used widely in medicine. Taken by mouth, it physically binds to acids and toxic substances in the stomach and digestive tract. Also, as an antidiarrheal, it was believed to work by adsorbing the diarrheal pathogen. For this reason, it has been used in several antidiarrheal medications, including Diar-Aid, Diarrest, Diasorb, Diatabs, Diatrol, Donnagel, Kaopek, K-Pek, Parepectolin, and Rheaban. It has been used for decades to treat diarrhea. Until 2003, Kaopectate marketed in the US also contained attapulgite. However, at that time, the U.S. Food and Drug Administration retroactively rejected medical studies showing its efficacy, calling them insufficient. Kaopectate's U.S. formula was changed to bismuth subsalicylate (pink bismuth). The next year (2004), an additional change in labeling was made; from then on, Kaopectate was no longer recommended for children under 12 years old. Nevertheless, Kaopectate with attapulgite is still available in Canada and elsewhere. Until the early 1990s, Kaopectate used the similar clay product kaolinite with pectin (hence the name). Construction Palygorskite can be added to lime mortar with metakaolin for period-correct restoration of mortar at cultural heritage sites. In human culture Palygorskite is known to have been a key constituent of the pigment called Maya blue, which was used notably by the pre-Columbian Maya civilization of Mesoamerica on ceramics, sculptures, murals, and (most probably) Maya textiles. The clay mineral was also used by the Maya as a curative for certain illnesses, and evidence shows it was also added to pottery temper. A Maya region source for palygorskite was unknown until the 1960s, when one was found at a cenote on the