GEMSTONE DNA “Blood diamonds” and “conflict minerals” are mined in war zones and used to finance brutal armed groups around the world. Now a new way of pinpointing a stone’s provenance may help prevent the illicit trade. The Texas-based firm Materialytics reports more than 95 percent accuracy in identifying the origin of everything from rubies to rough emeralds to minerals used in cell phones. The novel process begins when a laser beam converts a tiny amount of the rock into a bright micro-plasma, generating a spark recorded by a spectrometer. The light’s wavelengths create a unique spectral sequence, which is then detailed to 2 million data points per sample. Within minutes a tester knows if there’s a match in the firm’s database, which now contains 50,000-plus collected samples from more than 60 countries – some down to the exact mine where a gem originated. The technology is timely. Pending U.S. laws cod require importers to disclose whether products contain certain minerals from conflict regions. And the U.N.-endorsed Kimberley Process – a voluntary government-industry pact to keep blood diamonds off the retail market – is drawing fire for loopholes. Precise geology may be the key to pulling diamonds from the global rough.

SHRILL SCIENCE In a ranking of worst sounds, nails on a chalkboard rated first, outpacing scraping forks and Styrofoam squeaks. Why is it so awful? The ear canal is a long tube, wide open at the ear and closed at the drum. Studies show sounds from 2,000 to 4,000 hertz are highly amplified once inside, likely because parts of the human voice fall in that range – perhaps all the better to distinguish among vowels arid consonants, says sound researcher Michael Oehler. But when the tube collects the parts – of that shrill scrape also in the range, it can mean piercing reverb_and a physical reaction. Even imagining the sound may cause perspiration and increased heart rate, says Oehler of his next phase of research, which he hopes might spur vacuum cleaner and machinery makers to sweeten everyday sounds.

 

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