Light performance of a diamond is actually the way in which the light falling on it interacts with the stone. It can also be defined as the sparkling play exhibited by diamonds as light enters and exits the stone. It would be a real visual treat to see the bending and the reflection of light within the gemstone. Note that when light enters a diamond, it either gets leaked out or reflected. The light that leaks out of the stone would be invisible, whereas reflected light produces “brilliance”, making the stone look brighter. Of course, diamonds that boast superior light performance would reflect a maximal amount of light, making the gemstone extremely lustrous.

Things that Affect the Light Performance of Diamonds

The main thing that affects the light performance of a diamond is its cut quality. That is, the way in which the facets of a diamond are arranged and proportioned, can impact the way the stone reflects and bends the light. Normally, ideal round cut loose diamond specimens are known to have better light performance. As a result, the cut quality of round diamonds is usually graded according to the closeness of its facet arrangement to ideal cuts.

Components of Light Performance

The following are the four major components of a diamond’s light performance.

Fire – This comprises the flashes of rainbow colors that you see when light disperses within the stone. The fire of a diamond would be visible, mainly in a darker environment such as at night parties or candlelight dinners.

Brilliance – This comprises the light that reflects in and out of diamonds; an ideal-cut diamond would reflect the maximum amount of light, and would look brilliant. On contrary, a poorly cut diamond leaks too much light to exhibit the same effect.

Scintillation – This comprises the flashes of light that occur when a diamond or its wearer moves. Unlike fire, scintillation can be seen mainly only in a bright environment.

Contrast – The pattern of light and dark sparkles seen when viewed from the top, is termed as a diamond’s contrast.

How to Evaluate Light Performance in Diamonds

You can evaluate a diamond’s light performance only if you choose loose diamonds. For a mounted stone, the metal setting may limit its ability to properly showcase its light performance. For instance, choose a round radiant cut loose diamond and observe it under various lighting conditions. This way, you would be able to understand the measures of the above-mentioned components. Alternatively, you may simply check the cut grades of different stones; the ones with excellent cut quality would no doubt offer the best light performance.