Armenian bole, also known as bolus armenus or bole armoniac, is an earthy clay

Clay

Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

, usually red, native to Armenia

Armenia

Armenia , officially the Republic of Armenia , is a landlocked mountainous country in the Caucasus region of Eurasia...

. It is red due to the presence of iron oxide

Iron oxide

Iron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxides and oxyhydroxides.Iron oxides and oxide-hydroxides are widespread in nature, play an important role in many geological and biological processes, and are widely utilized by humans, e.g.,...

; the clay also contains hydrous silicate

Silicate

A silicate is a compound containing a silicon bearing anion. The great majority of silicates are oxides, but hexafluorosilicate and other anions are also included. This article focuses mainly on the Si-O anions. Silicates comprise the majority of the earth's crust, as well as the other...

s of aluminum and possibly magnesium

Magnesium

Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

.

Uses

Historically, it was used as an astringent

Astringent

An astringent substance is a chemical compound that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...

, prescribed against diarrhea

Diarrhea

Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

, dysentery

Dysentery

Dysentery is an inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhea containing mucus and/or blood in the faeces with fever and abdominal pain. If left untreated, dysentery can be fatal.There are differences between dysentery and normal bloody diarrhoea...

, hemorrhage, etc. Externally, it was used in strengthening plasters, against dislocations of the joints. Physicians sometimes also called it Rubrica Synopica, from the city of Synope

Sinop, Turkey

Sinop is a city with a population of 36,734 on İnce Burun , by its Cape Sinop which is situated on the most northern edge of the Turkish side of Black Sea coast, in the ancient region of Paphlagonia, in modern-day northern Turkey, historically known as Sinope...

, where it is supposed to be found.

It is also used in bookbinding

Bookbinding

Bookbinding is the process of physically assembling a book from a number of folded or unfolded sheets of paper or other material. It usually involves attaching covers to the resulting text-block.-Origins of the book:...

 for coloring, or applied to the edges during gilding, as a base for the gold leaf and to give the binding a greater depth and luster.

Finally, it was also used in the waterproofing of windmill

Windmill

A windmill is a machine which converts the energy of wind into rotational energy by means of vanes called sails or blades. Originally windmills were developed for milling grain for food production. In the course of history the windmill was adapted to many other industrial uses. An important...

sails. A popular mixture was: 10 liter water, combined with 0,75 liter linseed oil, 0,75 liter grease, and 1 kg of bolus.