Definition of Armenian bole

Armenian bole, also known as bolus armenus or bole armoniac, is an earthy clay, usually red, native to Armenia. It is red due to the presence of iron oxide; the clay also contains hydrous silicates of aluminum and possibly magnesium. Historically, it was used as an astringent, prescribed against diarrhea, dysentary, 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, where it is supposed to be found.