A light blue clay mineral occasionally used as a pigment. Aerinite has been found in Andorran murals dated to 1163 (Casas and Llopis, 1992). Aerinite has semitransparent prismatic crystals that are birefringent. It is resistant to chemicals, heat, and light although it changes to a green-blue shade when heated over 150 C.
Synonyms and Related Terms
aerinita (Esp.); erinite (It.)
A.Casas, J.Llopis "The Identification of Aerinite as a Blue Pigment in the Romanesque Frescoes of the Pyrenean Region" Studies in Conservation, 37:132-136, 1992.