2017-10-23 18:12:02
Trilobites: Uncovering an Overlooked Source for Iconic Alabaster Statues

18:12, October 23 77 0

Medieval and Renaissance sculptors carved gorgeous statues and religious icons from alabaster, a soft, creamy white stone similar to marble. Much of their work, from visages of the Virgin Mary to angels slaying demons, now reside in museums like the Louvre in Paris and others across Europe. But a mystery remains: Where did the alabaster come from?

“This is quite a frustration for museum art historians to have question marks everywhere,” said Wolfram Kloppmann, a geochemist at the French Geological Survey.

In a study published Monday in the Proceedings of the National Academy of Sciences, Dr. Kloppmann and a team of art historians, geologists and geochemists traced the origins of more than 60 alabaster statue. While many came from known quarries in England and Spain, the analysis of the stone also revealed an overlooked hub for alabaster production in the western French Alps. The site was a much richer source of the mineral than previously thought. The researchers’ work helped reconstruct an art trade route that existed across western Europe from the 12th to 17th centuries.

“This gives a picture of Medieval Europe in details we didn’t suspect before,” Dr. Kloppmann said.

The team asked museums and galleries across Europe and in the United States if they could take samples from their alabaster artwork for chemical analysis. They all said yes, allowing the team to investigate the origins of several royal and papal tomb figures, as well as the 14th century Carrying of the Cross from the Louvre, the 14th century the Archangel Gabriel from an Annunciation Group from the Cleveland Museum of Art and a 17th century seated greyhound originally from a gallery in London.

But the team had to collect samples as carefully as possible to avoid scarring the priceless works of art. They could not drill. They could not scrape. Instead, they used a tiny chisel to collect just a flake that measured only two millimeters from the base or rear of each statue.

At their lab, the scientists analyzed the flakes for sulfur, oxygen and strontium isotopes. Such signatures are fingerprints that made it possible to match the flakes to their original alabaster quarries. Of the 66 samples, 15 came from a quarry in the English Midlands to the west of Nottingham and three came from northern Spain. Both were historically well-known as centers for the alabaster trade.

The “alabastermen” of the English Midlands are believed to have provided the material from the 12th century until 1550 when religious icons were banned during a period of civil and religious turmoil in Britain known as the English Reformation, when the Church of England broke away from the Roman Catholic Church. Many of the works were destroyed in this period. Shiploads of alabaster artwork escaped the furnaces and were sent to France. This exchange was long thought to be one of the primary sources of the country’s alabaster.

But to the team’s surprise more than 20 of the statues they analyzed originated from near Notre-Dame-de-Mésage in the western French Alps. The quarry there operated for more than five centuries, supplying material for some of western Europe’s most important artworks.

“We did not know that this was really a major source of alabaster in western Europe,” said Dr. Kloppmann. “We discovered the French part of the story.”

Jane A. Evans, an isotope geochemist from the British Geological Survey who was not involved in the study, called the paper “well-constructed” and said the technique “could be extended to look at a wider range of carvings from differing periods, and they could extend their fingerprinting methods to incorporate other isotope and geochemical methods.”

Dr. Kloppmann said the next steps for their work is to analyze alabaster in Germany, Poland and Italy and perhaps from ancient Mesopotamia, as well as use their technique to detect alabaster fakes.