Later this year, the Gemological Institute of America (GIA) will introduce new wording in its diamond grading reports to reduce confusion about fluorescent diamonds. The update, expected in the fourth quarter, is one of the most important steps taken by a grading laboratory to explain this feature more clearly to both the jewellery trade and consumers.

Rapaport Intelligence Report explores what this change could mean for the diamond market. Fluorescence has had a long and complicated history. In the past, fluorescent diamonds often sold at premium prices. However, attitudes changed during the diamond boom of the 1970s and again after a grading controversy in South Korea in the early 1990s. Although later gemological research helped improve confidence in fluorescent diamonds, many buyers still view them negatively, and they often sell at discounted prices.

The report also looks at how these discounts have changed over the past six years through both strong and weak market conditions. In addition, the report explains two key questions: how fluorescence affects a diamond’s appearance and whether it influences its color grade. It also considers whether GIA’s new report comments could change how buyers view fluorescent diamonds.

The report revisits a long-debated issue—does fluorescence really affect a diamond’s beauty, or are today’s concerns mainly based on old perceptions that continue to influence buying decisions?

According to GIA, around 25% to 35% of all diamonds show some level of fluorescence. Greater transparency about this significant segment of the market could help improve confidence among both consumers and the jewellery trade.