A Light Performance™ Report is a diamond buyer’s assurance that they are judging with an “apples to apples” comparison. Each Report is the printed findings of the BrillianceScope Analyzer, an imaging spectrophotometer which measures with laboratory accuracy the three types of light a diamond emits.

Any diamond can have a Light Performance™ Report, and any jeweler can sell one (though you’re far more likely to find one at a GemEx Authorized Retailer.) If you wish, you may order a Light Performance™ Report on an unexamined diamond you’re considering purchasing.

Reading a Report
As you can see from the above “Guide Light Performance Analysis” there is no single measure of Light Performance™. That is because GemEx... in collaboration with “The Guide”... would have had to make an arbitrary decision on which of the three measured types of light (white light, colored light or scintillation) would carry the greatest weight. This depends on personal preferences. It’s important to know that superior performance in any of the three light categories yields a beautiful diamond. Only extremely rare (and very expensive) diamonds are superior in all three categories Knowing this is critical to matching a diamond to your budget.

Understanding the three light factors is very straightforward:

1. White Light, often referred to as “brilliance” among diamond professionals, refers to the area of the crown (top portion of the diamond above the girdle) that reflects light that appears white to the eye. This white light is usually the light entering the diamond that reflects back through the crown.
   
2. Colored Light or “fire” refers to the area of the crown that reflects spectral or colored light. It usually occurs when light entering the diamond reflects back through the crown after experiencing a “prism” effect within the diamond.
   
3. Scintillation or “sparkle” is a combination of the quantity and size of light return areas that flash and disappear as the light or the diamond is moved.
   
   If you’ve seen outstanding diamonds in the past, you may recall that the exceptional gems seem spectacularly white, attractively colorful, notably sparkling... or any combination of the three. Regardless of the combination, you noticed it because of the factor a Report measures scientifically: Light Performance™.