Tricorder identifies gems

Scientists are collaborating to develop a handheld spectroscopic device that can identify minerals on earth and other planets.

Robert Downs, associate professor of geosciences at The University of Arizona (UA), is working with M. Bonner Denton, a UA professor of chemistry and geosciences, to develop a pocket-sized Raman spectrometer to be used on the 2009 Mars rover. The technology being developed for Mars will help create handheld instruments for use on Earth.

"We're developing a tricorder," Downs said, referring to the Star Trek device used to analyse unknown materials.

One use for a hand-held instrument would be the identification of gemstones. Other ways to accurately identify minerals, such as X-ray diffraction and electron microprobe, require grinding a bit of the sample to powder or polishing the sample in a specific manner. Raman spectroscopy is a non-destructive alternative.

A Raman spectrometer fires a laser beam at the sample. The laser excites atoms within the sample, which then emit a very weak light of a wavelength in a pattern characteristic of the material. The material is identified by comparing it with reference information from a database.