Kermesic acid

Description

The primary red colorant found in Kermes. Kermesic acid is a water-soluble anthraquinone derivative extracted from the dried bodies of the female kermes insect, Kermes vermilio Planchon, found in southern Europe on the small evergreen kermes oak, Quercus coccifera.

Physical and Chemical Properties

Soluble in hot water, ethyl ether. Slightly soluble in cold water. In sulfuric acid, forms a violet red that turns blue by adding boric acid.

Composition	C18H12O9

Resources and Citations

• The Dictionary of Art, Grove's Dictionaries Inc., New York, 1996

• Judith Hofenk-de Graaff, Natural Dyestuffs: Origin, Chemical Constitution, Identification, Central Research Laboratory for Objects of Art and Science, Amsterdam, 1969