Feeling blue? Not like a Maya sacrificial victim

By Will Dunham

WASHINGTON (Reuters) - There was more than the obvious reason to feel blue for people offered in human sacrifice rituals by the ancient Maya to their rain god -- they were painted blue before being heaved into a watery sinkhole.

And it wasn't just any blue. It was Maya blue -- a vivid, somewhat turquoise-colored pigment used for about a millennium by Mesoamerican peoples to decorate pottery, figurines and murals that has long mystified scientists.

But now anthropologists from Wheaton College in Illinois and the Field Museum in Chicago have discovered how the ancient Maya produced this pigment and the role it played in important rituals at a famous Maya site in Mexico's Yucatan peninsula.

"Maya blue has long been of interest to scholars, both archeologists and chemists," Gary Feinman, curator of anthropology at the Field Museum who worked on the study, said in a telephone interview.

"The interest in Maya blue stems from the fact that it is a very durable pigment -- more durable than most natural dyes and pigments. It also stems from the fact it wasn't immediately obvious how it was made and what the key ingredients were."

The pigment resists age, acid, weathering, biodegradation and modern chemical solvents. Previous research had identified two ingredients as extract from the leaves of the indigo plant and an unusual white clay mineral called palygorskite.

These researchers did microscopic analysis on material found in a three-footed pottery bowl in the museum's collection dating from A.D. 1400 that had been used as an incense burner.

RAIN GOD CHAAK