Medicinal clay

Kaolinite ( ; also called kaolin) is a clay mineral, with the chemical composition Al2Si2O5(OH)4. It is a layered silicate mineral, with one "tetrahedral" sheet of silicate tetrahedra () linked to one "octahedral" sheet of aluminate octahedrons () through oxygen atoms on one side, and another such sheet through hydrogen bonds on the other side.

upright=1.3|thumb|Bentonite layers from an ancient deposit of weathering|weathered [[volcanic ash tuff in Wyoming]] thumb|Gray shale and bentonites (Benton Shale; Colorado Springs, Colorado)

Montmorillonite is a very soft phyllosilicate group of minerals that form when they precipitate from water solution as microscopic crystals, known as clay. It is named after Montmorillon in France. Montmorillonite, a member of the smectite group, is a 2:1 clay, meaning that it has two tetrahedral sheets of silica sandwiching a central octahedral sheet of alumina. The particles are plate-shaped with an average diameter around 1 μm and a thickness of 0.96 nm; magnification of about 25,000 times, using an electron microscope, is required to resolve individual clay particles. Members of this group

ancient Egyptian medical papyrus

Palygorskite or attapulgite is a magnesium aluminium phyllosilicate with the chemical formula ) that occurs in a type of clay soil common to the Southeastern United States. It is one of the types of fuller's earth. Some smaller deposits of this mineral can be found in Mexico, where its use is tied to the manufacture of Maya blue in pre-Columbian times.

thumb|Structure of illite mica – USGS

fine red Ancient Roman pottery with glossy surface slips made in specific areas of the Roman Empire

Therapeutic treatment of soaking in warm mud

clay material

thumb|Scanning electron microscope (SEM) photograph of smectite clay – magnification 23,500 – [[U.S. Geological Survey – Tuckup Canyon]] thumb|Typical cracks pattern of a smectite-rich bentonite after its desiccation and shrinkage

natural mixture of hydrated silicate clays colored with red iron oxide

thumb|Family of African Bush Elephants taking a mud bath in Tsavo East National Park, Kenya

Diosmectite (brand names Smecta, Smecdral) is a natural silicate of aluminium and magnesium used as an intestinal adsorbent in the treatment of several gastrointestinal diseases, including infectious and non-infectious acute and chronic diarrhoea, including irritable bowel syndrome diarrhea subtype. Other uses include: chronic diarrhea caused by radiation-induced, chemotherapy-induced, and HIV/AIDS-associated chronic diarrhea.

use of clay for health reasons

thumb|Rhassoul clay Rhassoul, or ghassoul (), is a cosmetic made of natural mineral clay mined from the Atlas Mountains of Morocco. It is mixed with water, sometimes with herbs or other substances, to clean the body. It has been used by Moroccan women on their skin and hair for centuries. Rhassoul contains silica, iron, magnesium, potassium, sodium, lithium and other trace elements.

thumb|Ayilo in Ghana Ayilo, also known as ayilor, hyile, and ferinkasa, is a Ghanaian term for bentonite clay. It is a baked solid white clay usually taken by pregnant women. They are usually baked into egg-shaped balls. Ewes call it agatawoe/agatawe, Gas called it ayilo, English call it kaolin and the Akans call it shirew/shile. Ayilo is mined primarily from a village in the Volta Region. It is first mined in the form of colored kaolin rocks from deep down the land. The rocks are then broken into smaller fragments and the colored parts are peeled off before pounding or grinding into powder. T