Due to its negligible effect on the overall appearance of a diamond, Fonder Diamond does not recommend selecting your diamond based primarily on its fluorescence grade. A 1997 study conducted by the GIA concluded that, "for the average observer, meant to represent the jewelry buying public, no systematic effects of fluorescence were detected." Generally, diamonds with faint to medium fluorescence are options for better value, as the difference in price can be invested in a higher cut or clarity grade.

In diamonds with Faint Yellow color grades (K and L), or even those at the lower end of Near Colorless (I and J), a high fluorescent grade may make the diamond appear whiter. The blue tones in its fluorescence can help to balance out yellow secondary tones. This may result in a diamond that looks as if its color grade is actually higher than it really is.

The GIA and the AGSL grade diamond fluorescence differently. While the GIA determine a diamond's grade by viewing it with the diamond's table facing down, the AGSL grades with the table facing up. AGSL also combines the two GIA grades of 'Faint' and 'None' into one: 'Negligible'. Keep in mind that if a diamond is graded 'Negligible', it may exhibit some subtle fluorescence under ultraviolet light.

While the majority of diamonds with fluorescence do so in a blue tone, other colors are possible. Rare yellow, orange, green and red fluorescence have been documented. These hues can increase the desirability of fancy colored diamonds if they complement their primary hue. A fancy yellow diamond with yellow fluorescence, for example, will have an intensity that appeals to many diamond customers, potentially raising the value of the stone.