Light Trace Performance
When a customer walks into a jewelry shop to buy a diamond, his choice of purchase relies heavily on the diamond's fire and sparkle − the features which bring life into it. This can be easily evaluated by our new FireTrace® technology.
OGI has scientifically developed a method for the evaluation of Diamond Light Performance based on a large number of combinations made up proportionately by various factors on the diamond facet. These include: total depth, table size, crown angle, crown height, pavilion angle, pavilion depth, lower-half, star length and culet.
As this Light Trace Performance technology uses a diamond's Three Dimensional model, the assessment includes each and every facet. Every facet contributes to the appearance of the stone as the beams of light come from all directions, split inside the diamond's facets and wander around before firing back a variety of lights. When Ideal result is achieved, the gem is evidently perfect in terms of its proportions and symmetry. The performance-based cut grade is available for Round Brilliant and all Fantasy stones.
Based on this technology OGI has launched a new Fire Lab Standard: OGF- OGI Fire Lab. This standard enables gemological and diamonds retailers to sort diamonds according to their Light Performance.
Example of one combination:
Fire Grade |
Excellent |
Very Good |
Good |
Fair |
Table Depth % |
56.8 |
60 |
61.4 |
64.2 |
Table Size % |
60.0 |
61.1 |
62 |
58 |
Crown Angle º |
30 |
34 |
36 |
36 |
Crown Height % |
11.5 |
13.19 |
13.8 |
15.2 |
Pavilion Angle º |
40.9 |
41.9 |
42.4 |
43.2 |
Lower Half % |
80 |
70 |
70 |
70 |
Star Length % |
50 |
50 |
50 |
50 |
Culet % |
0.01 |
0.01 |
0.01 |
0.01 |
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Fire Grade Standard:
 Excellent |
 Good |
 Very Good |
 Fair |
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Several OGI machines can be used for this purpose. Following are examples of such uses.
Combining Fire Technology within an OGI Rough System such as the Scanox Marker, Scanox Planner and OGIMarker enables optimal planning in terms of both the weight and light reflection of the diamond, with the aim of reaching the "excellent" mark for the polished stone. That is, optimal weight and optimal light reflection can both be predicted while the diamond is still in its rough condition. This allows you to decide on the best way to process the stone so as to reach the maximum Light Trace Performance evaluation in line with the 4 Cs.
Combining this technology with an OGI Polished System such as MegaFire, Scanox Proportion or MegaScope instruments enables estimating the degree of light reflection contained in the diamond. Within seconds you can see a graphic illustration of the crown and pavilion and the amount of light reflection projected from the geometrical shape of the diamond.
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The Light Performance Standard is based on three factors: Brightness, Fire and Scintillation.
Brightness: Describes the refractions and reflections of white light coming from the diamond in "face-up" position. Brightness is created primarily when light enters through the table, reaches the pavilion facets and is then reflected back out through the table, where the light is most visible to your eyes.
Fire: Describes the fiery, rainbow color–flashes emanating from the diamond. This is white light broken-up into the colors of the spectrum.
Scintillation: Describes the refraction and reflection of the light that flashes on and off that flashes off as the diamond, the observer or the lighting moves. |
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