How Lasers Could Help Fingerprint Conflict Minerals

New submitter carmendrahl writes "Diamonds might get most of the media's attention, but they're not the only minerals being sold to underwrite militias. Two chemistry teams are developing portable instruments that can detect an elemental fingerprint in mineral ores, to verify that the samples don't come from militia-controlled mines. One technique uses laser-induced breakdown spectroscopy (PDF), which vaporizes a small amount of an ore sample with a high-energy laser pulse, and detects elements in the sample by their characteristic light emission. The other technique couples the laser ablation to a mass measurement and a scanning electron microscope."