Thought some of you might find this as interesting as I did. Many of you may already know these nuances but I love learning and wanted to be educated so here you go!I asked John the following questions I as I’ve been in the process of buying my CBI:
Me: Why do some CBI diamonds have 34.6 and 40.9 crown and pavilion angles verses others with 34.5/40.8 etc. and how does that affect different aspects of performance (light return, fire, etc.)? For example, I had heard that a smaller table = more fire, and less white light verses a larger one?
John:
1. Numbers mythos
Proportions numbers on reports are good in a broad sense. Average diamonds can be classified. Some blind estimations can be made (as HCA does) but it’s no better than drawing a chalk-outline of a person. You get the gist of shape but no detail. That’s why sound advice-givers on PS ask for ideal-scope or ASET in addition to the average-numbers.
When it comes to Crafted by Infinity no report can be as precise as what we do with the actual diamonds. Here is what I mean: The scanners used at the labs acknowledge +/- 0.1 degree angular error on every single measurement (see “Accuracy” information on this page). And remember a number such as 40.9 is an average of eight different measurements. So that’s eight potential inaccuracies within that data-point.
For example: I have attached two grading reports to this email. They are for the same diamond. (See screenshot)
- Check the 2014 grading report: Terrible scan. That’s apparent from the computer generated ASET imprint. We knew there was likely scan-error present, but the diamond was on-hold already and the buyer didn’t mind.
- Five years later the diamond returned to Antwerp. We polished off the brand-inscription (explained here) and sent it back through AGS for a new report.
- Now check the 2019 grading report: This is a better scan. But remember, nothing has been touched on crown or pavilion. Look how the angles are different (they aren’t) and how the depth changed (it didn’t).
- Most importantly, look at the computer generated ASET imprints between the reports. It is the same diamond. But the non-contact scanner generates wildly different computer-generated ASET renderings based on the fact that it’s not repeatable enough to capture precision at the level we execute it.
- Sidebar: You may also notice we challenged the SI1 down to SI2. This is related to us upping our standards, while the labs seem to have grade-creep the other way. We have become increasingly sensitive to protecting our retailers.
CBI Fire
Pricescope dialogue spans a wide range of generic output. In general terms the advice works. But you are above the clouds with Crafted by Infinity. We are chasing a completely different goal to produce bigger, bolder, bursts of fire. For us it’s about compound mirror size and integrity. Doing that absolutely trumps a few microns of crown height a “smaller table” creates. And no other production we know of is pursuing or achieving this with our consistency.
Here is a PS thread where I explained it: https://www.pricescope.com/community/threads/cbi-fire.242606/#post-4388614
Here is a PS thread where I reiterated the explanation, with some photos: https://www.pricescope.com/communit...-2-18-e-vs1-center.248820/page-2#post-4546075
2. Girdle description
Me: I also noticed that most stones have thine to medium girdles but some have thin- slightly thick. That has no affect except putting a bit more weight in the middle right?
John: Negligible. It’s a matter of microns. See this article I composed. Many people presume girdle ranges are equally graduated. They are not. https://www.hpdiamonds.com/en-us/blog/blog-article/44/girdle-thickness.htm
Also I forgot to mention that John responded the same evening I asked these questions (I had asked them at 7:30pm and he responded by 9pm). I cannot get over the outstanding level of customer service and kindness of the entire staff at HPD. And this was not the first time I got a response late into the night from their incredible staff, who have bent over backwards for me. I can’t WAIT to share my story once my ring is done. I have nothing but total respect for this company and their product. I recommend them with 10 gold stars!
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