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Fluorescence has long been a subject of debate in the diamond industry. Relating to a phenomenon that is evident in about 25 percent to 35 percent of stones, it relates to visible light being emitted by certain diamonds when heir atoms are excited by an external light source. 

Most commonly diamonds fluoresce when they are exposed to ultraviolet rays, such as the sun or fluorescent lamps. The light that is emitted is generally bluish, and in a minority of cases is yellow or lightly orange. 

Once the diamonds are separated from the ultraviolet light source, they cease to fluoresce.

Whether FLUORESCENCE is desirable or not depends on who you consult. Some say blue FLUORESCENCE enhances a diamond’s appearance, and especially diamonds in the I to M color ranges. Indeed, they state, bluish FLUORESCENCE can make a faint yellowish diamond appear more colorless. This has resulted in a situation by which one can sometimes demand higher prices for fluorescent diamonds in the near colorless to faint yellow color ranges.

However, the opposite is generally true for fluorescent diamonds in the D to H color range. There it is said that a bluish FLUORESCENCE causes the stone to appear a hazy or oily.


According to a report recently published by Reuters, Russia’s state-controlled diamond mining company is now considering creating a jewelry brand that exclusively uses fluorescent diamonds.

 “We are completing talks with several major companies in different regions,” said Sergei Ivanov, the company’s chief executive, speaking to the news service.

Ivanov did not name the retailers that Alrosa has been in touch with, but he insisted that the fluorescent diamonds will be marketed by third parties, with the diamond mining company having no plans to start its own retail business.

“Our aim is to supply fluorescent polished diamonds – cut by Alrosa or its clients – to retailers and provide marketing support, including jewelry design if needed,” he told Reuters.

Alrosa says it plans to begin fluorescent stones in a year under the brand name of “Luminous Diamonds.”

Research conducted on Alrosa’s behalf in the United States and China showed that millennial consumers in particular liked the fluorescent stones for their unusual quality. “We saw that it can become a fashionable product and interesting for these young people,” Ivanov told Reuters.

The research also showed that women in liked the diamonds, so the company has decided to promote its “Luminous Diamonds” to independent female consumers.

“It will be a special line. A diamond which glows in a night club, in a theater or even in the rays of sun,” Ivanov said. “We see this demand in opinion polls and are sure that we will convert it into sales.”

Alrosa’s “Luminous Diamonds” brands, featuring fluorescent diamonds, is targeting independent female consumers, as in this screenshot from a promotional video.


But is Alrosa’s program based on fact, or it mainly a marketing exercise? Several years ago the Gemological Institute of America conducted a study in which it assembled four sets of six diamonds, with each group representing a different color grade – E, G, I, and K. The diamonds in each set were similar, with the exception being the intensity of blue FLUORESCENCE. Diamond graders and average observers were asked to look at the stones in controlled conditions and judge their appearance.

According to GIA, for the average observer no systematic effects of blue fluorescence on the face-up appearance of the various groups of diamonds were detected, and even experienced observers did not consistently agree on the effects of fluorescence from one stone to the next.

Indeed, according to GIA blue fluorescence had a negligible effect on the face-up appearance of all diamonds in the colorless or near-colorless grade ranges, except for a sometimes slight improvement when the intensity of the fluorescence was very strong.