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Brilliancescope by Gemex: Anatomy of Diamond Light Performance.
Many consumers are constantly asking us for advice on their prospective diamond purchases.They list their candidates and provide the diamond's numbers off the Lab reports and in some cases list additonal Cut information derived from either the Sarin (www.sarin.co) or Megascope (www.ogisystems.com) machine.
For round brilliant diamonds it is easier to advise against purchase
when the numbers clearly indicate an overly shallow or deep stone that will display poor to mediocre light performance.
The difficulty presents when consumers provide "numbers" that look very good and/or ideal. The term "ideal" for the purposes
of this article is used in the context of the Marcel Towlkowsky Ideal-Cut, the "numbers" calculated by Towlkowsky
in the late 1900's to result in a diamond that displays superior light performance.
The Brilliancescope, manufactured by Gemex Systems (www.gemex.com) is an imaging spectrophotometer that measures how well a diamond refracts and focuses light.
Past all of the numbers, a diamond's beauty is the result of how it returns light to your eye. When a diamond's facets have been cut to the correct size, angle, and aligned correctly, they act as mirrors, refracting light with great intensity and with an even distribution across the entire surface of the stone.
Different Diamond Cut Configurations
Brilliancescope Machine by Gemex Systems (Mequon, Wisconsin).
The Brilliancescope measures light performance in a controlled lighting environment consisting of six lighting angles.
The machine provides an objective method of evaluating the intensity, distribution, and interaction of light output by measuring
light that is returned through the crown.
The technology used in the BrillianceScope was originally developed
by UGTS and LambdaSpec Instruments.
UGTS was the tech development division and LambdaSpec
was the Marketing section that licensed the technology.
Randy Wagner, at the time at UGTS was one of the original developers of the technology and was awarded the patent in 1996-1997.
Kurt Schoeckert came on board in 1998, They formed Gemex, Inc.
and bought all of the technology rights from UGTS and LambdaSpec.
All optics used in the Brilliancescope are off the shelf parts or custom made by major optics companies such as Rodenstock and CRI.
Whether or not her diamond ring grabs your attention will be determined by the Cut quality of the stone; the better the Cut, the greater the light performance.
The diamond ring moves and tilts as she moves her hand. This tilting changes the entry angle of light through the diamond's facets.
The BrillianceScope standardizes these movements by precisely changing the angle of the light source to illuminate the diamond.
The Brilliancescope has six lighting angles to measure the stone;
five positions are reflected light and one position is diffused light which also displays the level of the diamond's Cut Symmetry and Contrast. If the diamond cutter has aligned all of the facets correctly, they will act as 'mirrors' refracting entering light back to your eye with great intensity and with an even distribution across the entire surface area of the stone.
Approximately 800,000 diamonds to date have been evaluated and registered into the Gemex database to determine the range of light performance.
These Evaluation Scales are linear graphs that show how a specific diamond performs in relation to the industry standards for reflection performance.
The Brilliancescope is user friendly and easy to operate. The Operator must calibrate the Brilliancescope at a minimum of once a week or it will automatically shut down and prevent a diamond from being run.
The Operator must insure that the diamond is clean. No smudges, oil, or lint anywhere on the diamond's surface. The glass plate must also be inspected and cleaned of lint and smudges.
Next the operator places the diamond table
down onto the glass plate and makes sure that it is centered in the Bullseye.
The cover is now closed and light analysis performed.
This is the output.
The Operator fills in the ID data of the diamond, then clicks on the LPA/WEB button which sends the output directly to Gemex for evaluation. After careful review by Gemex engineers, the Operator receives e-mail notification regarding the submitted scans.
Approved gifs can be immediately downloaded and provided to interested consumers.
Rejected scans come with an explanation and
a request to correct the problem and re-submission.
The Brilliancescope measures three components of light:
1.white light,
2.colored light,
3.scintillation.
White light is the evaluation of the diamond's overall area in
returning bright white light from the crown from each of 5 reflectance lighting angles.
Color light looks at each lighting angle and determines where bright color light is returning from the crown.
Scintillation refers to changing colors,the sparkle of light rays coming from the stone when it moves and/or the light source changes.
Arrows below point to "freckles" and "rice krispies" which are on the diamond's periphery and indicate scintillation.
Operator clicks on the LPA button that sends the data to Gemex for inspection and review.
How is the output evaluated.
At Gemex Headquarters in Mequon, WI., GemEx engineers review these submitted scans for accuracy.
Each scan is screened for over 20 possible human errors and technical issues such as proper and timely machine calibration, clean diamond,
clean glass plate, and proper centering of the diamond, to assure that the scan is accurate. If human error or technical problems are found
the scan is rejected and the Operator immediately notified of the problem, asked to correct it, and then to re-scan the diamond.
If the scan is approved on the first go around, it is sent to a second check station and again reviewed for the same 20 + check list.
If it passes that final check, the report is printed and mailed to the Operator/customer. If there is no hard copy Light Performance™ Report,
you cannot be assured that the scan was put through these very important checks by Gemex, and therefore you
cannot assume that the results are accurate or repeatable. This is the reason that only GemEx can issue Light Performance Reports
and does not allow BrillianceScope users to unilaterally
provide scan results or print their own reports.
This rigorous screening system by Gemex assures that Brilliancescope results for all Operators are accurate, valid, and repeatable.
RESULTS:
Light Performance results are depicted in two ways: 1. Bar graphs, and 2. Five light views and one view in diffused light showing symmetry and Contrast.
One criticism leveled against the BrillianceScope is that it does not provide easy to understand number results. This is not true.
The first prototype of the BrillianceScope did indeed use a number scale of 1 to 10. Consumers responded by asking for scores that were
visually indistinguishable from each other such as a 9 versus an 8.5
(Both are in the Very High cataegory).
Gemex therefore decided to abandon the number scale
and instead use bars because
light performance is a continuum not a stepped sequence.
A 9.3 is not visually discernable or necessarily superior to that of a 8.8.
Number results are provided by the Brilliancescope and can only be seen by the Operator via a special click-through.
Both White light and Color light data are calculated in terms of percentages.
A percentage of area returning
white light is calculated and used to determine
where on the scale this diamond scores compared
to other diamonds of the same shape.
Results from the Brilliancescope are repeatable within a very useful range which is the width of the bars on the scales.
The analogy is to two race cars; one traveling at 100 MPH, the second at 105 MPH. Your eye cannot discern +/- 5 MPH.
On the other hand, slight changes in the numbers make it appear as if
the score is not repeatable. For example, a score of 8.8 versus 9.3 would be seen by a consumer as being qualitatively
different with an attached value of "good" versus "better".
Your eye can not pick up these tiny percentages of variation.
Comparative measurement avoids this problem.
The 5 light views show you the intensity, distribution, and interaction of the measured light components. Light view 6 shows Symmetry and Contrast under diffuse light conditions.
Contrast (Black Areas) under Diffuse Light as well as Symmetry are shown in Light View 6. Note the excellent contrast in the 60-60 diamond which has a facet alignment significantly different from that of an Ideal Cut round diamond.
Here are the informative Brilliancescope results and Cut data for this 60-60 diamond.
One of the criticisms leveled against the Brilliancescope by certain Ideal Cut companies is that their diamonds do not perform well
because the machine tends to favor certain "brands" over others. This is not true.
The Brilliancescope is an equal opportunity evaluator and evaluates light performance based on proper facet alignment, facet size, and
facet angle. The results from this 60-60 diamond clearly illustrates this fact.
Why Light Performance and Not "Numbers" Are Key.
In a previous article posted to www.diamondtalk.com we have stressed the importance of light performance over the "numbers"
in determining a consumer's diamond purchasing decision.
The article is here:
Diamonds and Gemex
We agree with our colleagues that "seeing is believing" and
we always advise consumers to make every effort to physically "see" and compare as many diamonds as possible in order
to make an informed buying decision.
It is our opinion based on working intensively with Gemex and the Brilliancescope over the past four years, that this
technology is currently the very best available to give consumers accurate information on a diamond's light performance.
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