A research team has found a way to identify a rare blue diamond. Their method is termed as the 'diamond fingerprinting method'. The team includes a Penn State University minerologist, Peter J. Heaney, professor of geosciences, and researchers like Jeffrey E. Post, Smithsonian's curator of gems and minerals, and Sally Eaton-Magana from the Naval Research Laboratory.%%The team conducted its experiments at the Smithsonian's National Museum of Natural History in Washington on the Hope Diamond. Blue diamonds are known to react with ultraviolet rays. They exposed the hope Diamond to the rays and noted that the diamond glowed with a reddish-orange phosphorescence colour for five minutes, and the emitted rays were of varying wavelengths, which became a marker for a blue diamond. Another way to determine was by noting the time span it takes for the intensity of the phosphorescence to reduce by half. The study says that a combination of the two provides a unique fingerprint, but further tests are necessary to confirm the findings, as only the Hope Diamond and few other blue diamonds react with the reddish-orange phosphorescence when exposed to ultraviolet light, while most remain blue in colour. The conclusions of the experiments have been published in Geology. What was certain through the experiments was that each blue diamond displayed a unique ratio of wavelengths of red and blue light and half-life of its phosphorescence.%%Researchers also tested two synthetic blue diamonds and a treated diamond, which produced different results from natural diamonds, drawing the conclusion that the method for synthetics is different than that for naturals. According to Dr. Heaney, the team’s identification method can make people aware of the conflict diamonds and help them make better choices in their purchases. The method can also be employed for finding diamonds produced from larger diamonds.