Research Shows Possibility for Identifying, Tracking Blue Diamonds

Researchers recently conducted a study revealing the possibility that blue diamonds, through spectroscopic analysis, can be individually identified and distinguished from synthetic or treated diamonds. The report confirms that all blue diamonds have a red phosphorescent component.  

As part of the study, scientists directed an ultraviolet light at the famous Hope Diamond, which caused the blue stone to glow red-orange for about five minutes.

Other blue stones known to be natural were tested, including the second-largest known blue diamond - the Blue Heart, the Portuguese Diamond and 64 other blue diamonds, many of which came from the Aurora Butterfly – a collection of 240 stones temporarily on display at the Natural History Museum.

Of these stones, only five did not phosphoresce like the Hope Diamond. The report does not claim that the five are not natural blue diamonds, only that they were of a different type from the other blue diamonds that did phosphoresce. Further details were not provided.

Diamonds of other colors do not phosphoresce; rather, they emit visible light only as long at they are stimulated with ultraviolet radiation.  

Boron impurities in the carbon makeup of a diamond give it its blue color. A combination of this and nitrogen in the diamond, which makes a yellow hue, is most likely responsible for the reddish glow.

This phosphorescent characteristic of blue diamond can distinguish synthetic and treated diamonds from natural stones, and it may also provide a way to fingerprint individual blue diamonds for identification purposes, according to the study, published in Geology, by a team of researchers from the Naval Research Laboratory, the Smithsonian Institution and Penn State University.

The researchers also tested three artificial blue diamonds (doped with boron), but they did not have the same reaction to the ultraviolet light as the natural blues.

One of the scientists, Penn State Professor of Geosciences Peter J. Heaney also noted that understanding the phosphorescence of blue diamonds may make it possible to physically track them and ensure they have come from legitimate sources, a major focus of Heaney’s work.