Diamonds: Selected Information
KT

THE days of daring diamond heists may soon be numbered with the development of a "fingerprinting" technique that can identify individual gem-stones and make it easier to recover stolen jewellery.
Scientists have designed a method of diamond identification that scans and recognises the unique colour pattern or "signature" for individual gems.
Called microspectrometry, the developers claim that it should allow stones to be identified even after they are altered or cut, and make it easier to spot fakes.
The procedure was created by United States scientists who conducted tests on sapphires and spinnels, a low-value red stone often used as a cheap alternative to rubies. The method works by recording the wavelengths of ultraviolet light that are reflected by an area of a gemÕs surface measuring just a hundredth of a centimetre across.
The scientists found that each stone gave off a different wavelength signature.
While the differences are invisible to the human eye, the use of ultraviolet light makes them particularly pronounced, a report in the journal New Scientist reveals.
Identification of individual stones is currently difficult because there are so many, and the purity of the highest-quality specimens makes them quite similar.