Red Ochre

Technically, the name ocher is used only for the product extracted from ochrous sand by a process of fine grinding that eliminates the sand, leaving the finer grains of clay. Hematite, also called sanguine, is a red iron oxide (the names are from Greek and French words for blood); ochers that contain hematite crystals may be red-orange, red, and even red-violet. (Delamare 15)

Delamare, François and Bernard Guineau. Colour: Making and Using Dyes and Pigments. London: Thames & Hudson, 2000.

‘Red ochre contains iron, and the iron molecules act like compass needles,’ explained Professor Giancomo Chiari of the Department of Minerological and Petrological Sciences at the University of Turin. He said that in the few minutes between daubing red ochre onto wet clay, and the time it dries, the molecules realign themselves towards the direction of magnetic north. (Finlay 643/6836)

Finlay, Victoria. Color: A Natural History of the Palette. New York, NY: Random House Trade Paperbacks, 2002.

 

Sennelier Red Ochre
Purchased in Paris, March 2011 

All are very opaque, absolutely permanent and have the same general properties as the pure red oxides. Inexpensive, excellent covering power, and weather resistant. Strong absorber of ultraviolet light. (Mayer 96)
The earth reds should be replaced whenever possible by their counterparts the Mars colors and the bright red oxides, which are cleaner and more powerful. (Mayer 97)

Mayer, Ralph and Sheehan, Steven. The Artist's Handbook of Materials and Techniques. New York: Viking Press/Viking Penguin, 1991.

Ceiling of the Red Cows. Left wall, Axial Gallery, c.20000 BC. Lascaux, France. 

Web. 27 March 2011. http://www.lascaux.culture.fr [English → XHTML Version → Resources → Cow painted on the ceiling]