Caput mortuum (pigment)

This article relies largely or entirely on a single source. Relevant discussion may be found on the talk page. Please help by introducing citations to additional sources. Find sources:  –  ·  ·  · scholar · JSTOR (March 2021)

Ferric oxide

Caput mortuum (Latin, meaning "dead head", and variously spelled caput mortum or caput mortem), also known as cardinal purple, is the name given to a purple variety of haematite iron oxide pigment, used in oil paints and paper dyes. It was a very popular colour for painting the robes of religious figures and important personages (e.g. art patrons).

The name for this pigment may have come from the alchemical usage, since iron oxide (rust) is the useless residue (caput mortuum) of oxidization. It was originally a byproduct of sulfuric acid manufacture during the 17th and 18th centuries, and was possibly an early form of the copperas process used for the manufacture of Venetian red and .^[1]

References[]