New Technology Gives on-Site Assessments

The ability to tell the difference between crystals that formed naturally and those formed by human activity can be important to archaeologists in the field. This can be a crucial bit of information in determining the ancient activities that took place at a site, yet archaeologists often wait for months for the results of laboratory tests.

Now, however, an international team of physicists, archaeologists and materials scientists has developed a process that can tell in a matter of minutes the origin of samples thousands of years old. The new device is easily portable and works by "lifting off" the spectral fingerprint of a material with infrared light.

The first material tested was the mineral calcite, commonly found in rocks such as limestone, which forms over millions years in sediments. These rocks can also contain the mineralized shells of sea creatures. Archaeological sites may also feature calcite that was a part of ash, plaster, or other building materials.

In the latest issue of the journal Advanced Materials, online November 17, Stefano Curtarolo, associate professor of mechanical engineering and materials sciences and physics at Duke University, and Kristin Poduska, associate professor of physics at Memorial University in Newfoundland, and their colleagues at the Weizmann Institute of Science in Israel, describe the new approach, which has already been successfully tested in archeological sites in Israel.