Wow! How soon will these certificates start circulating? Excited to see how they correlate.
Part of my brain says, snatch up non branded great cuts now!
I found the following "Score Card" on the IGI website during my research for a perfect stone this week:
It seems that the evaluation of the light performance is mainly based on the proportions. A pricescope ideal diamond would be the perfect IGI light score near to 100.
Edit:
Here are some additional information:
Diamond Cut Grading
With our diamond cut grading guide, you'll gain insight into the intricacies that determine a diamond's light performance and sparkle.www.igi.org
„Note that light performance analysis is based on external proportions and does not account for dense clarity characteristics/reduced transparency.“
„The Ideal-Scope Representation, generated with ray-tracing software, conforms to the diamond’s specific parametric averages“
In other words: The averaged proportions are used in a software that simulates the reflections.
Ok I've used their charts to get a grading for a diamond I have and previously scored with HCA …
What are the stats in the diamond you scored? Mind sharing?
As long as it has reasonable lowers and stars% the combination looks like a winner to me.This is the diamond rated under both scoring systems https://www.igi.org/verify-your-report/?r=LG618455187
More info here:
and here:
Diamond Cut Grading
With our diamond cut grading guide, you'll gain insight into the intricacies that determine a diamond's light performance and sparkle.www.igi.org
I am sure there are a million and one questions.
If anyone was curious about what was taking a lot of my PS time
I am not an official spokesperson so any information is not official.
I was one of many working on it, John Pollard and I did most of the system design work with support from many people.
To answer some questions,
At this launch reports are only issued, optionally, for the “Exceptional” range. Will expand to Superior next.
We have a ton of respect for Garry and the HCA in the end we found out we agreed with the HCA much of the time but in some cases we disagreed.
We do take more parameters into consideration, such as lower girdle/halve angles and upper girdle/halve angles this changes the edges a lot.
Garry was instrumental in training both John and myself as well as many others.
I still learn something from him nearly every time we talk even after all these years.
Howdy everyone,
More info here:
and here:
Diamond Cut Grading
With our diamond cut grading guide, you'll gain insight into the intricacies that determine a diamond's light performance and sparkle.www.igi.org
I am sure there are a million and one questions.
If anyone was curious about what was taking a lot of my PS time
I am not an official spokesperson so any information is not official.
I was one of many working on it, John Pollard and I did most of the system design work with support from many people.
To answer some questions,
At this launch reports are only issued, optionally, for the “Exceptional” range. Will expand to Superior next.
We have a ton of respect for Garry and the HCA in the end we found out we agreed with the HCA much of the time but in some cases we disagreed.
We do take more parameters into consideration, such as lower girdle/halve angles and upper girdle/halve angles this changes the edges a lot.
Garry was instrumental in training both John and myself as well as many others.
I still learn something from him nearly every time we talk even after all these years.
Is this image generated from the diamond report numbers?
Yes,
Table,ca,pa from the report.
Star% and Lower% are common values.
Thanks for the clarification. How would I generate an image from numbers, or is that the preserve of special access?
The software to do so is no longer for sale.
Ok.
The other diamond I bought
Verify Your Report
Ensure authenticity & accuracy of your report here. Verify your gemstone report online for complete confidence in your precious investments.www.igi.org
With the IGI scoring
Light performance = Exceptional
Brightness = Exceptional
Fire = Exceptional
Contrast = Exceptional
and with HCA
Cut Advisor Score of 1.5
Light return = Excellent
Fire = Very good
Scintillation = Very good
Spread = Very good
Would it be possible to see the computer generated image from the IGI PDF report figures for this diamond too, if easy, and if you have time
Thanks.
Its not going to show much as the base combo works very well.
Do you have a spin video link so I can estimate the other values not on the report?
This is the video
Loupe360
loupe360.com
That's one of the things commonly passed around that is false.Granted, we also tell ppl that a crown height of 14 isn’t necessarily going to give “exceptional” fire.
That's one of the things commonly passed around that is false.
Many of the combinations with slightly lower CH do favor brightness over fire across a wide range of lighting.
However it is 100% false that in lighting conductive to fire that they can't knock your socks off as much as any other combo.
Good to know!
Lately, there have been a lot of 15.5-16 crown heights touted as great for fire. But according to you, those combo need to have longer lowers, is that correct?
Just trying to get my details straight, and as always, really appreciate your input here on PS!