Gcal changing cut grading.

[Mlh]

Diamonds.net - New Cut Grade Aims to Distinguish Best Diamonds

A US grading laboratory has introduced a new cut grade designed to differentiate higher-quality diamonds from the “excellent” score that most polished stones receive. Gem Certification & Assurance Lab (GCAL) unveiled its 8X grading report this week, highlighting a need to set apart...

www.diamonds.net

 

[PrismBaby]

Very neat! Thanks for sharing this.

 

[Karl_K]

meh another closed and marketing centric grading system.

 

[oldminer]

GCAL is a highly competent and well run laboratory operation. They are free to offer what they consider a better solution than GIA if they wish. I always look for the good things when I see innovation. All or some parts of what they intend to offer may become important to Pricescope shoppers seeking the very best cut diamonds.

I also understand that dealers and some experts may not share my enthusiasm for innovation. Tradition and stability are also important parts of the diamond trade. Technology breeds disruption. Consumers dictate what the market and dealers eventually will choose to offer. Many more diamonds deserve to be graded by GCAL. Maybe this innovation will prove a successful concept. I look forward to seeing the system in action.

 

[Karl_K]

Im not against innovation I'm against useless closed metrics/tests and marketing fluff.
It will remain useless because it is closed.
Someone tells me they can predict for example a diamond with more fire and I ask them how and they say that's propriety and offer no proof they actually measure anything I'm going to call BS.

For example one question I have had for a long time:
How does coloring areas of leakage purple/blue equal measuring brilliance?
Leakage is just a part of what could make a diamond less bright, one with more leakage could be many time brighter in the real world.
All my opinion.

 

[oldminer]

Karl, your questioning is really better in a separate thread. Labs that provide performance numbers and cut grades use a lighting model for all their measurements. I trust most of them use a reasonable model, but there is no guaranteed conformity of the lighting models being used. Lighting differs and results must also differ. Still, there seems to be some reasonable agreement that the results and grades make sense. AGSL, GIA and GCAL use reasonable lighting models and there is no reason to suspect an agenda or a bias is going on. If anything is really wrong, our eyes will tell us pretty quickly and our tools, such as Sarine / Helium and DiamCalc will also sound alarms. Otherwise, I think there is room for improvement and better description of the cream of the crop, super-ideal cut diamonds. We need to see what is being offered and how it meets our expectations, both visually and technically. I get lots of technically bright consumers who ask what separates a premium cut ideal from a standard AGS000. I think we need more hard data. Taking highly precise measurements and reporting them on lab reports to clearly define how a diamond is cut to superb standards rather than normal standards is sensible. Technical buyers like facts rather than fluff words which don't truly explain the added care that has been given to each super-ideal.

 

[CutMonkey]

As a consumer, I think this is a step in the right direction. Obviously, the more open the better, but it's clear that the current GIA 3 EX and AGS 000 are inadequate for differentiating premium ideal cuts from others. My hope (and hunch), is that this will push the other grading labs to step up their game, which will be a win for everyone.

 

[flyingpig]

Who is going to be their clients? Probably lab grown diamond producers?

 

[headlight]

Interesting... to receive their 8x designation a stone must have hearts & arrows. There are nicely performing stones that are not. Additionally, there is scrutiny over what is legit H&A so this will be interesting. But as @oldminer alluded to, the more tools availed to consumers, the better.

 

[cflutist]

Who is going to be their clients? Probably lab grown diamond producers?

HP Diamonds launched their new website last night. Their CBI diamonds come with all 3 lab reports, GIA, AGS, and GCAL. Please have a look and see for yourself.

 

[flyingpig]

HP Diamonds launched their new website last night. Their CBI diamonds come with all 3 lab reports, GIA, AGS, and GCAL. Please have a look and see for yourself.

I think the main selling point of the GCAL report to vendors is they also do high quality videos and reflective images. Outside WF and JA, noone else does this well consistently.

I like the overall package GCAL delivers to vendors. Having that said, I would still want natural diamonds dual certed with GIA and GCAL.

 

[yssie]

As @Karl_K said - define “optical brilliance”, “fire”, and “scintillation”, and explain how you measure doe those criteria and evaluate those measurements, and then I’ll have enough information with which to judge whether or not I believe you. If you can’t or won’t, then it’s exactly what Karl called it - marketing fluff.

Edit - https://www.gcalusa.com/cut-analysis.html
Sure smells like marketing fluff. From the description - a plain mirror would do very well in this optical brilliance analysis.