Armenian bole, also known as bolus armenus or bole armoniac, is an earthy clay, usually red, native to Armenia but also found in other places. The term Armenian was later referred to a specific quality of the clay. Originally used in medication, it has also been used as a pigment, as a poliment or base for gilding, and for other uses.[1] It is red due to the presence of iron oxide; the clay also contains hydrous silicates of aluminum and possibly magnesium.
- ^ Greenfield, Jane (2002). ABC of bookbinding: a unique glossary with over 700 illustrations for collectors and librarians. New Castle (Del.) Nottingham (GB): Oak Knoll press The Plough press. p. 5. ISBN 978-1-884718-41-0.