What is the basis for the selection of the 3 independent measures, brilliance, sparkle and intensity?
The scientific basis and experimental support for selecting these measures is found in the US Patents cited below. Click here to read the related answers.
Why did ImaGem decide to adopt the direct measurement of a stone’s light behavior as the preferred method to evaluate the quality of a stone?
Over the past ten years an important scientific finding by ImaGem is that when the results of these three independent measures are combined into a light behavior grade.
How did ImaGem establish that its measures of light behavior reflect what the human eye sees?
Gemologists and jewelers participated in tests in which they ranked series of stones of a range of sizes and qualities on their perception of beauty. There was a high correlation between these rankings and the combination of the three light behavior measures.
Please indicate what the terms brilliance, sparkle and intensity mean in consumer terms.
In terms commonly used within the gem industry, brilliance is synonymous with “light return”, sparkle with “life” and intensity with “contrast”. Click here to read the definitions of the three terms.
What is meant by the term balance when combining the three measures into an overall light behavior grade?
Balance among the three measures is vital; reaching the theoretical maximum on any measure does not necessarily result in the highest light behavior grade. Rather scoring in the excellent range on all three measures yields an Excellent + rating.
What can be learned from the light behavior image on the report?
The pattern is a visual representation of how a diamond reacts with light and is a powerful tool for selling a stone. The light behavior image is unique and distinctive to each diamond and may be used to differentiate it from other diamonds which have a different pattern of light distribution.
What distinguishes this light behavior service from other companies that measure light performance?
ImaGem has developed a system to distinguish between appearances of diamonds based on direct measurement of light behavior. The direct measurement of light behavior approach takes into account the color, clarity and nuances in a diamond which cannot be done through a modeling approach.ImaGem has also introduced intensity as an important measure of light behavior which distinguishes ImaGem’s light behavior from others. Also ImaGem provides numerical values for brilliance, sparkle and intensity and a grade based on these values.ImaGem’s direct measurement of light behavior can evaluate diamonds of various shapes, sizes as well as branded cuts.Scintillation and fire while historically have been considered in describing the quality of a diamond are difficult to measure because of lack of operational definition. In ImaGem’s direct measurement of light behavior, aspects of scintillation and fire are measured by the three measures of light behavior under repeatable conditions.
Why did ImaGem elect not to include fire or dispersion in the measures used?
Under the lighting conditions that ImaGem utilizes, fire, which is the breakup of light into colors, is already incorporated into the measurements of brilliance and sparkle. In tests run with gemologists and jewelers we have found that a balance of high scores on the three measures, brilliance, sparkle and intensity, correlates with their ratings of beautiful stones. In other words, the three light behavior measures are sufficient to identify beautiful stones. In terms of the scales used by ImaGem, three “Excellents” are required to obtain the highest overall Light Behavior rating.A basic problem in separately measuring and reporting fire is the lack of a definition which can then be translated into direct measurement. The lighting environment that favors the observation of fire has pinpoints of light. The level of fire can increase or decrease depending on the light. We know of no standard procedures either for defining the exact lighting model or the movement of the stone when observing fire.Gemologists and jewelers will no doubt keep using a demonstration of the fire in a stone as an effective tool in selling. The newest version of VeriGem is a powerful selling tool that displays various light attributes including fire to consumers. The direct measurement of light behavior is a new objective tool designed for screening, evaluating and selling stones.
How did ImaGem determine the normal lighting conditions employed?
ImaGem’s direct measurement of light behavior from its inception regarded human perception as an important factor in how the optics and lighting was set up. Different lighting conditions and optics were tested to find a particular setup which repeatably would provide readings highly correlated with data obtained from human perception of diamonds.
What patent protection does ImaGem have for its methodology for measuring light behavior?
ImaGem has three issued patents in the United States and other patents have been issued in several other key markets. The total number of claims exceeds several hundred and includes many claims directed to direct measurement of light behavior of a diamond.
What is the role of the gemologist in producing light behavior reports?
As with full grading reports, the gemologist reviews and approves the light behavior findings before the report is printed.