shape
carat
color
clarity

CBI diamonds - which of these are the best option?

Mikeeb123

Rough_Rock
Joined
Aug 17, 2018
Messages
22
I'm based in the UK and have a $4800 budget to replace a lost ring. From another thread I think the CBI diamonds look the way to go. I've made contact with one of the dealers in London and they've offered me the following. Which one would you go for, and do you think they represent fair value? All of the certificates are also below. Many thanks.

0.70ct E-VVS2 at 4,640US$ vat excl – 3,698£ vat excl – 4,437£ vat incl.
upload_2018-8-23_14-15-12.png
0.70ct E-VS1 at 4,336US$ vat excl – 3,455£ vat excl – 4,146£ vat incl.
upload_2018-8-23_14-16-3.png
0.70ct D-VS1 at 4,460US$ vat excl – 3,555£ vat excl – 4,265£ vat incl.
upload_2018-8-23_14-16-51.png
0.77ct G-VS1 at 4,218US$ vat excl – 3,361£ vat excl – 4,033£ vat incl.
upload_2018-8-23_14-17-29.png
 

Rpb

Shiny_Rock
Joined
Apr 2, 2018
Messages
354
My preference would be .77 G as that would give you best value for money. Lovely proportions too....
 

OoohShiny

Ideal_Rock
Premium
Joined
Apr 25, 2014
Messages
8,228
All of them will look awesome :))


If you are buying from London, does that mean you'd be able to get to London in person?

I think it would make sense to see all of the options in person, if you can get there - that would enable you to determine if the G has any tint visible to your eyes, and if it does, if it actually bothers you!
(You should ask to see stones in a variety of lighting, including flat, natural light by a window.)

What setting will it be in? Solitaire? Halo? Bezel?

Bezel or Halo will hide the side view, meaning any tint will be a lot harder to see because the head-on performance is so good.


For me... I am ultra-picky about clarity and 'eye-clean' so would go for the one with the cleanest table in a VS, or go straight to the VVS so it was definitely 'mind-clean', but the 0.77 should be visibly larger when side-by-side with the 0.7s, so it's a tough call... :))
 

Dancing Fire

Super_Ideal_Rock
Premium
Joined
Apr 3, 2004
Messages
33,852
Strange, The AGS reports you posted are different from the CBI sold by HPD here in the US. Your reports does not say "crafted by Infinity". :confused:
 

Mikeeb123

Rough_Rock
Joined
Aug 17, 2018
Messages
22
All of them will look awesome :))


If you are buying from London, does that mean you'd be able to get to London in person?

I think it would make sense to see all of the options in person, if you can get there - that would enable you to determine if the G has any tint visible to your eyes, and if it does, if it actually bothers you!
(You should ask to see stones in a variety of lighting, including flat, natural light by a window.)

What setting will it be in? Solitaire? Halo? Bezel?

Bezel or Halo will hide the side view, meaning any tint will be a lot harder to see because the head-on performance is so good.


For me... I am ultra-picky about clarity and 'eye-clean' so would go for the one with the cleanest table in a VS, or go straight to the VVS so it was definitely 'mind-clean', but the 0.77 should be visibly larger when side-by-side with the 0.7s, so it's a tough call... :))

Yes, we can get to London easily. It will be a single diamond solitaire
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,791
First off -- all lovely choices. We normally see HPD provide CBI stones here in the USA. You get a high quality stone and superb customer service that is largely based on the awesomeness of HPD's owner, @Wink.

That said, I understand you needing/wanting to work with a local guy. Maybe @Wink can comment more on them?

My comments below on the two stones I like.

0.70ct E-VS1 at 4,336US$ vat excl – 3,455£ vat excl – 4,146£ vat incl.
upload_2018-8-23_14-16-3.png

Absolutely gorgeous E color with crisp VS1 clarity. With your previous stone being a D IF, I think at a certain level you and the Mrs probably appreciate this stone even though it's a little smaller than the bigger 0.77ct G stone I also like and will comment on here in a second. Also, the liklihood either of you could tell a D and E apart is very slim as it's hard for experts to do so without referring to master color stone sets.

Love the 56% table, and that 34.5/40.7 angle combo is my favorite. Also I really like the 76 LGF's as the arrows will be a little on the fatter side (which I vastly prefer). Put CBI's proprietary spin on the cut quality and this stone will IMPRESS! :love: :love:


0.77ct G-VS1 at 4,218US$ vat excl – 3,361£ vat excl – 4,033£ vat incl.
upload_2018-8-23_14-17-29.png

If you and your girl are not color sensitive enough to discern the G from the E colored stone, then this would be my choice. It's not massively bigger, but just ever so slightly.

Not by coincidence, you get that 56% table again with 34.5/40.8 angle combo. This stone will produce lots of fire and be absolutely gorgeous! This stone does have slightly narrower arrows at 77% LGF; however, most people probably won't notice that.

Really, I think it comes down to color. If you guys prefer E, then go with the smaller stone above. If the G works, get the slightly bigger size. Both will be phenomenal. So happy for both of you, especially knowing where you came from -- this is going to be like night & day difference! :cool2:
 

OoohShiny

Ideal_Rock
Premium
Joined
Apr 25, 2014
Messages
8,228
Strange, The AGS reports you posted are different from the CBI sold by HPD here in the US. Your reports does not say "crafted by Infinity". :confused:

I think the diamond is the same as this one on the HPD site

https://www.hpdiamonds.com/en-us/diamonddetail/HPD9639

I can't see that it shows CIB on this one either?
Strange - maybe they've stopped adding the laser engraving and/or grading report text?

Perhaps @Wink would be able to confirm!
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,791
Strange - maybe they've stopped adding the laser engraving and/or grading report text?

Perhaps @Wink would be able to confirm!

@Wink will know best, but my guess is that maybe the CBI marks on the AGS report are specific to diamonds they stock? Maybe stock that is readily available to the CBI dealer network isn't branded the exact same on the certificate?

Here is one that has the CBI markings on the cert, but standard AGS girdle inscription.

https://www.hpdiamonds.com/en-us/diamonddetail/HPD7895
 

OoohShiny

Ideal_Rock
Premium
Joined
Apr 25, 2014
Messages
8,228
Yes, we can get to London easily. It will be a single diamond solitaire
Excellent :))

In that case I think whatever any of us says is relatively moot - you should ask if you can see them all with your own eyes, so you can ascertain if any of the inclusions bug you and whether or not a G will suit!

You could also consider this 0.73 F VS1 as a middle-ground that would still look colourless :)
https://www.hpdiamonds.com/en-us/diamonddetail/HPD9233
 

whitewave

Super_Ideal_Rock
Premium
Joined
Feb 29, 2012
Messages
12,331
I’d pick the last one. Only because at this point you are nit picking and I personally like the slightly smaller table. I have a .56G and it is completely white, so that gives you a slight savings.

Let me give it a bath and I’ll take a quick pic.
 

lovedogs

Super_Ideal_Rock
Premium
Joined
Jul 31, 2014
Messages
17,908
I think all will look great, and seeing them in person is important. For me, the G represents the best value, but I'm also not color sensitive. But you can't go wrong here :)
 

WinkHPD

Ideal_Rock
Trade
Joined
May 3, 2001
Messages
7,516
Strange - maybe they've stopped adding the laser engraving and/or grading report text? Perhaps @Wink would be able to confirm!

The posted internet PDF does not include the CBI logo. The printed and laminated AGS report continues to have the Crafted by Infinity logo. This is important for clients to register with insurance, since that logo confirmation should ensure replacement with another CBI in case of theft or loss.

Another critical difference with those internet posted PDFs: They make the plotted inclusions and blemishes look far more severe than the actual report. I am posting an actual report copy here so that you can see the difference. Our showroom dealers regularly express shock when receiving the actual report, after having looked at the online version first. The difference made by conversion to PDF really is dramatic.

Diamnd-grading-report-9073.jpg

Wink
 

Dancing Fire

Super_Ideal_Rock
Premium
Joined
Apr 3, 2004
Messages
33,852
Wink, Why CBI no longer inscribe logos on the girdle like their earlier stones?
:think: Neither does WF.
 

icy_jade

Ideal_Rock
Joined
May 1, 2009
Messages
6,131
Bonus is that they are all a bit larger than your previous diamond. They all look great. At this level it takes eagle eyes to spot differences I think so I’ll pick based on size and color.

Echoing what the others have said, G if not color sensitive (since the biggest), E vs1 if you are sensitized and D if you are super sensitive. Pls do take your time to see the diamonds under neutral (not store) lighting.
 

TreeScientist

Brilliant_Rock
Premium
Joined
Jan 16, 2018
Messages
1,256
My vote is for the D/VS1. Only 100£ more than the E/VS1, so might as well go for the highest color in this case. :) Especially since you already had a D color stone to begin with. Rule out the VVS2. Anything over VS1 is overkill, especially with a CBI stone, as they are all eye-clean.

Color is an area where you can actually see a difference. Clarity grades beyond VS1 don't make any difference. It's purely a bragging statistic once you get to the VVS and IF clarity grades.

I'm sure you'll be happy with a CBI. All of their diamonds are gorgeous. :)
 

OoohShiny

Ideal_Rock
Premium
Joined
Apr 25, 2014
Messages
8,228
The posted internet PDF does not include the CBI logo. The printed and laminated AGS report continues to have the Crafted by Infinity logo. This is important for clients to register with insurance, since that logo confirmation should ensure replacement with another CBI in case of theft or loss.

Another critical difference with those internet posted PDFs: They make the plotted inclusions and blemishes look far more severe than the actual report. I am posting an actual report copy here so that you can see the difference. Our showroom dealers regularly express shock when receiving the actual report, after having looked at the online version first. The difference made by conversion to PDF really is dramatic.

Diamnd-grading-report-9073.jpg

Wink
Thank you, Wink! :)

Wink, Why CBI no longer inscribe logos on the girdle like their earlier stones?
:think: Neither does WF.
Do they only engrave the little 'i' symbol now??
 

WinkHPD

Ideal_Rock
Trade
Joined
May 3, 2001
Messages
7,516
Wink, Why CBI no longer inscribe logos on the girdle like their earlier stones?

:think: Neither does WF.

Time has proven that bad actors may remove inscriptions from diamonds before fencing them. The chance of that rises if there’s a specific brand inscription on the girdle. However, any good Samaritan finding a lost diamond can use the AGS number to contact the lab. AGS would contact CBI as the submitter-of-record. CBI could trace that diamond to the selling dealer. The dealer could contact the owner. That’s the hope in case of loss. Unfortunately >99% of diamonds lost are never returned.

This is why CBI moved the logo to the grading report. The client will still have that report, even if the diamond is stolen or lost, and having the logo on that report serves as undeniable proof to the insurance company of the diamond’s pedigree.

Wink
 

BlingDreams

Ideal_Rock
Premium
Joined
Jul 12, 2015
Messages
2,262
I’d go for the .77 G stone. I just saw CBI diamonds in D-G together and darned if they didn’t look almost indistinguishable!
 

Mikeeb123

Rough_Rock
Joined
Aug 17, 2018
Messages
22
Thank you everyone for your help - it really is appreciated.

The supplier is also going to see if there are any other CBI's that are similar to the above early next week, and so I may well post those up too to get your advice.

Thank you so much for your help - it's very much appreciated. Have a great weekend all!
 

crbl999

Brilliant_Rock
Joined
Jan 21, 2010
Messages
562
.77 G VS1 is my favorite. The G will face up icy white and maximizes size. The .70 E VS1 would be my second top pick. Great choice if color sensitivity is a factor.
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,791
Thank you for your help so far everyone.

I'm going to see the diamonds on Tuesday to make a decision. Did anyone else have any preference on which stone they'd prefer on paper from the above (including the https://www.hpdiamonds.com/en-us/diamonddetail/HPD9233 that @OoohShiny recommended)

Thank you so much for your feedback above @sledge

No problem, glad I could help.

In regards to the new F VS1 presented above. Converting USD to Pounds and then adding about 16.7% for tax, duties, etc it appears the stone is around 4,000$ GBP all in. Looking strictly at dollars, it's nearly a wash with the G VS1.

That said, let's talk size for a minute.
  • E VS1 @ 0.707cts = 5.71 x 5.73 mm
  • F VS1 @ 0.730cts = 5.77 x 5.81 mm, stone is ~0.06 mm > E and ~0.11 mm < G
  • G VS1 @ 0.773cts = 5.88 x 5.91 mm, stone is ~0.11 mm > F and ~0.17 mm > E
These dimensions are marginal at best. Most humans with normal vision can start to detect a size difference around the 0.20 mm range. While visible in a side to side comparison, the difference is very minor and not memorable or significant in my opinion, meaning you won't walk away going "wow, that one stone was sooo much bigger". And if you don't see them side by side, odds are you wouldn't even know there was a size difference.

To put numbers into the equation:
  • 0.06 mm = 0.002362205 inches, which is about 1/500th of an inch
  • 0.11 mm = 0.004330709 inches, which is about 1/225th of an inch
  • 0.17 mm = 0.006692913 inches, which is about 1/150th of an inch
To put it mildly, yes, there is technically a size difference but in human terms you won't ever see the size difference between these 3 stones. For that reason, I would choose based on the best color and/or angles.
  • E VS1 @ 0.707cts = 56.4 table, 61.6 depth, 34.5/40.7, 76 LGF
  • F VS1 @ 0.730cts = 56.0 table, 61.4 depth, 34.3/40.7, 76 LGF
  • G VS1 @ 0.773cts = 56.5 table, 61.6 depth, 34.5/40.8, 77 LGF
Before I start, I will say I am being extremely nit picky here, and much of this is based on my preferences and how I would pick a stone. In reality, all 3 stones will be drop dead gorgeous and in all seriousness I'd be happy to own any of them. It would be arguable if the differences I list would be visible to the naked eye. However, we must nit pick to get to a final selection so here goes.

I like the table the best on the F, but I like the 34.3 crown the least. Smaller table equals more fire, and larger crown equals more fire. For me, the sweet spot is a 34.5/40.75. This crown falls just short of what I'd prefer to see. Additionally it offers no clear advantage on color, size or cost. So I would eliminate.

The E & G are nearly identical stones. I'm not even going to debate or consider a tenth of a difference on table size because outside of the E being technically smaller and consequently "better", I'm not sure any human eye could see any appreciable difference. Crown angles & depths are the same. Pavilion is different by a tenth on the angle but also slightly deeper, so no measurable difference here either. The smaller the LGF means the fatter the arrows. I like fat arrows so I prefer the 76 LGF on the E stone but again at 1% difference I question how much our eyes could actually discern IRL and not under magnification.

This gets me back to the size and color differences. I personally don't think the G has a clear advantage on the size, but for color sensitive people the E does have an advantage. And coming from a D color stone I think you may appreciate the E a little more.
 

cflutist

Ideal_Rock
Premium
Joined
Jul 12, 2004
Messages
4,052
I have read this many times from @Wink
Put all three in a slotted tray in random order without you knowing which is which.
Look at them in all sorts of lighting
Pick the one that speaks to YOU the most
 

sledge

Ideal_Rock
Premium
Joined
Apr 23, 2018
Messages
5,791
I have read this many times from @Wink
Put all three in a slotted tray in random order without you knowing which is which.
Look at them in all sorts of lighting
Pick the one that speaks to YOU the most

Yeah, or do that. :lol:

I know I make it too hard sometimes. Forgot he was able to see all 3 in-person.
 

John P

Ideal_Rock
Trade
Joined
May 1, 2008
Messages
3,563
I like the table the best on the F, but I like the 34.3 crown the least. Smaller table equals more fire, and larger crown equals more fire. For me, the sweet spot is a 34.5/40.75. This crown falls just short of what I'd prefer to see. Additionally it offers no clear advantage on color, size or cost. So I would eliminate.
Actually @sledge, I would mention that the old rule of thumb about 2D crown height doesn't apply in our controlled production. I posted the below in another thread not too long ago, but it applies in this CBI-specific thread as well.

*
Crafted by Infinity’s fire proposition is the same, diamond to diamond.

We have a specific vision for each performance component. We also have the luxury of producing every diamond ourselves. To that end we're achieving 3D cutting goals where symbiosis between the collective facet groups notably outpaces some of those old rules of thumb.

This is a popular topic among our jewelers, and I’m going to share some of my training material here.

First…

What is fire? -vs- What is dispersion?

Many people refer to dispersion and fire interchangeably. But they are not the same.
  • Dispersion is caused by diamond material. It’s white light split into fans of rainbow colors and exiting the diamond.
  • Fire is physiological. If a portion of a dispersive fan enters your pupil your brain sees a colored flash, or ‘fire.’ But if the whole fan enters your pupil you see a white flash, or possibly nothing.
To elaborate: If a strong dispersive fan passes over your eye and is wider than your pupil diameter you see a colored flash. If that dispersive fan is smaller than your pupil diameter the light is recombined and you see a white flash. If it's too small or weak you see nothing. In optimal cases, a single wide fan passing across your pupil may cause you to see a full suite of shifting chromatic colors, as on the left.

ps-dispersion-color-versus-white2.jpg

So dispersion is not fire. Dispersion creates potential to perceive fire. But whether you see fire depends on the lighting, how the diamond was crafted and your own physiology.

Diamond fire origins and crown height

Beautiful antique diamonds are known for producing large, fluid colored flashes (usually at the expense of brightness). This cutting style evolved in an age when one rough diamond octahedron would be shaped into a single polished diamond. The most economical way of making that crystal attractive was to ‘brute’ the rough into a roundish shape – initially done by rubbing two diamonds cemented on sticks against one another. Once girdled, thick pavilion mains were polished on the bottom and extremely high crowns were fashioned on top. This let dispersive fans grow large as they passed through generous diamond material. Fire was the primary attribute and appeal of those cuts. In fact, the descriptor ‘fire’ comes from cutters in those days, who were maximizing the reflections of fire from the gas lamps under which they worked.

Economics and lighting changes

That all changed around 1900. The rotary saw allowed factories to get two diamonds from one rough crystal. Mechanical girdling evolved and jewelry store lighting shifted from gas lamps to incandescent, halogen and LED. Diamond industry economics and lighting advances saw crowns getting lower and lower & pavilion mains getting thinner and thinner. By 1980 the tables had turned - pun intended. From gas lamps and fire-priority to spotlighting schemes and brightness/fire/scint.

ps-1880-1980-economics2.jpg

The proliferation of bright halogens and LEDs even stimulated a parade of cuts with additional facets, marketed as having ‘extra sparkle.’ True enough, those cuts sizzled like crazy when blasted with spotlights, but most had such reduced performance qualities in normal lighting that they didn’t survive for long. The Leo diamond is a notable exception.

Old 2D rule: Higher crown = More fire.

This rule of thumb has been passed down for over a century, and for good reason; All things equal, a diamond with a high crown and small table should produce more visible fire than a diamond with low crown and large table. It’s simple physics: More crown means more room in the diamond for dispersive fans to grow. Viola…

So it’s a good old rule. But it comes from a world of 2D proportions.

Crafted by Infinity 3D approach

We don’t rely on crown height for primary fire. Our proposition is fueled by 3D compound mirrors. It’s part of the consistent vision I mentioned; marrying brightness-intensity with fire-efficiency.

Brightness intensity is easy. Any factory can produce bright diamonds if they choose optimal angles and polish with even nominal consistency. Any production can also increase fire using leaps in 2D crown height.

But marrying top brightness intensity with fire-efficiency involves stepping into another world. It requires planning and 3D focus to keep internal reflections unbroken and of specific size. It also requires extra time, expense of weight and fine-tuning of diamond material. This is not graded by labs or mentioned on reports. But successfully applied, the result is larger internal mirror surfaces, and larger, more intense dispersive fans your pupils will see as colored flashes. "More Fire."

ps-compound-mirror-graphic2.jpg

So there's your answer: Within our controlled production any minute differences in 2D proportions are negligible. The results come from all facets working together, which permits some variance as long as the greater goal is achieved.

In fact - and this shocks many of the jewelers I train - the classically considered ‘fire-facets’ actually take a backseat to some key minor facets in our proposition.

cbi-dispersion-fire-compound-mirrors-crown-height2.jpg

Visible implications

The performance characteristics have been consistently described here so I'll leave that to the community. I would just add that our goals for fire deliberately extend to low-lighting conditions where the observers’ pupils become more dilated. The reason I bring that up is because it's where you'll find the 3D compound mirror proposition notably outpaces 2D crown height in bringing fire.

Summary

Basic brightness continues to be numbers-predictable in round diamonds. It’s why the HCA is so simple but effective.

But as it relates to the question here, especially in such a narrow proportions range, achieving 3D symbiosis between collective facet groups can transcend some of the old rules of thumb.

That was a long read. I hope it's interesting and stimulating.

*
Original thread here.
https://www.pricescope.com/community/threads/cbi-fire.242606/#post-4388614
 

HappyNewLife

Ideal_Rock
Premium
Joined
Mar 25, 2010
Messages
2,534
biggest one would be my pick. That G will be very white, especially in a super duper ideal CBI. And BIG!
 

Mikeeb123

Rough_Rock
Joined
Aug 17, 2018
Messages
22
Thanks @John Pollard - so which ones of the above diamonds would you go for?


Actually @sledge, I would mention that the old rule of thumb about 2D crown height doesn't apply in our controlled production. I posted the below in another thread not too long ago, but it applies in this CBI-specific thread as well.

*
Crafted by Infinity’s fire proposition is the same, diamond to diamond.

We have a specific vision for each performance component. We also have the luxury of producing every diamond ourselves. To that end we're achieving 3D cutting goals where symbiosis between the collective facet groups notably outpaces some of those old rules of thumb.

This is a popular topic among our jewelers, and I’m going to share some of my training material here.

First…

What is fire? -vs- What is dispersion?

Many people refer to dispersion and fire interchangeably. But they are not the same.
  • Dispersion is caused by diamond material. It’s white light split into fans of rainbow colors and exiting the diamond.
  • Fire is physiological. If a portion of a dispersive fan enters your pupil your brain sees a colored flash, or ‘fire.’ But if the whole fan enters your pupil you see a white flash, or possibly nothing.
To elaborate: If a strong dispersive fan passes over your eye and is wider than your pupil diameter you see a colored flash. If that dispersive fan is smaller than your pupil diameter the light is recombined and you see a white flash. If it's too small or weak you see nothing. In optimal cases, a single wide fan passing across your pupil may cause you to see a full suite of shifting chromatic colors, as on the left.

ps-dispersion-color-versus-white2.jpg

So dispersion is not fire. Dispersion creates potential to perceive fire. But whether you see fire depends on the lighting, how the diamond was crafted and your own physiology.

Diamond fire origins and crown height

Beautiful antique diamonds are known for producing large, fluid colored flashes (usually at the expense of brightness). This cutting style evolved in an age when one rough diamond octahedron would be shaped into a single polished diamond. The most economical way of making that crystal attractive was to ‘brute’ the rough into a roundish shape – initially done by rubbing two diamonds cemented on sticks against one another. Once girdled, thick pavilion mains were polished on the bottom and extremely high crowns were fashioned on top. This let dispersive fans grow large as they passed through generous diamond material. Fire was the primary attribute and appeal of those cuts. In fact, the descriptor ‘fire’ comes from cutters in those days, who were maximizing the reflections of fire from the gas lamps under which they worked.

Economics and lighting changes

That all changed around 1900. The rotary saw allowed factories to get two diamonds from one rough crystal. Mechanical girdling evolved and jewelry store lighting shifted from gas lamps to incandescent, halogen and LED. Diamond industry economics and lighting advances saw crowns getting lower and lower & pavilion mains getting thinner and thinner. By 1980 the tables had turned - pun intended. From gas lamps and fire-priority to spotlighting schemes and brightness/fire/scint.

ps-1880-1980-economics2.jpg

The proliferation of bright halogens and LEDs even stimulated a parade of cuts with additional facets, marketed as having ‘extra sparkle.’ True enough, those cuts sizzled like crazy when blasted with spotlights, but most had such reduced performance qualities in normal lighting that they didn’t survive for long. The Leo diamond is a notable exception.

Old 2D rule: Higher crown = More fire.

This rule of thumb has been passed down for over a century, and for good reason; All things equal, a diamond with a high crown and small table should produce more visible fire than a diamond with low crown and large table. It’s simple physics: More crown means more room in the diamond for dispersive fans to grow. Viola…

So it’s a good old rule. But it comes from a world of 2D proportions.

Crafted by Infinity 3D approach

We don’t rely on crown height for primary fire. Our proposition is fueled by 3D compound mirrors. It’s part of the consistent vision I mentioned; marrying brightness-intensity with fire-efficiency.

Brightness intensity is easy. Any factory can produce bright diamonds if they choose optimal angles and polish with even nominal consistency. Any production can also increase fire using leaps in 2D crown height.

But marrying top brightness intensity with fire-efficiency involves stepping into another world. It requires planning and 3D focus to keep internal reflections unbroken and of specific size. It also requires extra time, expense of weight and fine-tuning of diamond material. This is not graded by labs or mentioned on reports. But successfully applied, the result is larger internal mirror surfaces, and larger, more intense dispersive fans your pupils will see as colored flashes. "More Fire."

ps-compound-mirror-graphic2.jpg

So there's your answer: Within our controlled production any minute differences in 2D proportions are negligible. The results come from all facets working together, which permits some variance as long as the greater goal is achieved.

In fact - and this shocks many of the jewelers I train - the classically considered ‘fire-facets’ actually take a backseat to some key minor facets in our proposition.

cbi-dispersion-fire-compound-mirrors-crown-height2.jpg

Visible implications

The performance characteristics have been consistently described here so I'll leave that to the community. I would just add that our goals for fire deliberately extend to low-lighting conditions where the observers’ pupils become more dilated. The reason I bring that up is because it's where you'll find the 3D compound mirror proposition notably outpaces 2D crown height in bringing fire.

Summary

Basic brightness continues to be numbers-predictable in round diamonds. It’s why the HCA is so simple but effective.

But as it relates to the question here, especially in such a narrow proportions range, achieving 3D symbiosis between collective facet groups can transcend some of the old rules of thumb.

That was a long read. I hope it's interesting and stimulating.

*
Original thread here.
https://www.pricescope.com/community/threads/cbi-fire.242606/#post-4388614
 

whitewave

Super_Ideal_Rock
Premium
Joined
Feb 29, 2012
Messages
12,331
I’d go for the biggest. I have a CBI G and it is white.
 
Be a part of the community Get 3 HCA Results
Top