Ice Age Chemists - Archaeology Magazine Archive


Ice Age Chemists	November 23, 1999
by Norman Hammond

Analysis of unused pigment found in the Troubat Cave in southeastern France reveals that Ice Age artists were the first to create artificial colors to decorate their caves. Natural pigments such as yellow goethite and red hematite, both iron oxides, and black charcoal and manganese dioxide were used to create the extraordinary 30,000-year-old images of mammoths, bison, horses, and deer in Chauvet Cave in southern France. But at Troubat Cave in the Pyrenées, say scientists from the French National Museum, these same materials appear to have been heated to change their color before they were applied to the walls 10,000 years ago. This gave the artists a range of shades in the yellow-red part of the spectrum in delicate gradations lacking in the natural goethite and hematite pigments.

"A well-known property of goethite is that it dehydrates and transforms to hematite when heated to 250-300°C, with a corresponding color change," the team stated in the journal Archaeometry. "As early as the Roman period painters used goethite as the basis for recipes to obtain red pigment and hues ranging from yellow and orange to deep purple, a process practiced well into the twentieth century."

According to researchers nearly a quarter of the collected specimens had been heat-treated directly in the fire; the presence of maghemite, an iron oxide formed in the presence of organic matter like charcoal, confirms that the pigments were not baked in a protective container. Most of the artificial pigments were concentrated in one part of the cave, suggesting that the area was dedicated to pigment preparation.

Noting that, at the famous cave of Lascaux, artists some 17,000 years ago deployed various shades of yellow, pink, red and brown, the scientists now hope to test their findings on samples from those cave paintings.