Ochre derives from Greek ōchra (yellow ochre), from ōchros (pale, pale yellow). But while the word is Greek, the substance is immeasurably older than any language. Archaeological evidence documents human use of ochre pigments stretching back at least 100,000 years, making ochre the oldest art material in the world — older than any surviving language, any civilization, any technology except the most basic stone tools.
The earliest known use of ochre comes from Blombos Cave in South Africa, where red ochre crayons and engraved ochre pieces dating to approximately 75,000 BCE have been discovered. Earlier still, ochre fragments showing signs of deliberate grinding and processing have been found at sites in Africa dating to over 100,000 years ago. These findings suggest that the use of pigment — for body decoration, ritual, or symbolic communication — is one of the oldest distinctively human behaviors.
Ochre is a naturally occurring clay pigment, colored by iron oxide minerals. Yellow ochre (limonite) contains hydrated iron oxide; red ochre (hematite) contains anhydrous iron oxide; brown ochre (goethite) is intermediate. The transformation from yellow to red can be achieved by heating — a discovery made by prehistoric peoples who effectively invented the first synthetic pigment by heating yellow ochre to produce the more vivid red.
The cave paintings of Lascaux, Altamira, and Chauvet — spanning roughly 17,000 to 36,000 years ago — used ochre extensively. The Paleolithic artists ground ochre into powder, mixed it with water, animal fat, or other binders, and applied it to cave walls with brushes, pads, and by blowing through hollow bones. The warm yellows, reds, and browns of these paintings are almost entirely ochre-based.
In the ancient Mediterranean world, ochre was commercially traded. Specific regions were known for producing high-quality pigments: Sinope on the Black Sea produced a famous red ochre (hence sinopia), and various Aegean islands exported distinctive varieties. The Greeks and Romans used ochre extensively in fresco painting, pottery decoration, and cosmetics.
Ochre remains in use today, both in fine art and in industrial applications. It is one of the few pigments that has been in continuous human use from the Stone Age to the present — a hundred-thousand-year tradition of coloring the world with earth.