Fire difference between BGD stones

[Double E]

Recently there was a thread looking into the potential difference of fire between CBI stones , and has been brought to the attention of fellow PSers. Thanks for John's extensive information, we are allowed for more insight into the topic.

This at the same time has created another question in my mind. With BGD being an equally reputable vendor, is there any difference of fire between stones within their top lines actually? Appreciated if any expert or experienced BGD clients could provide a better picture of this~

 

[FL_Sol]

I have been wondering the same. When watching the CBI, WF, and JA comparison videos that another user posted, I felt like my BGD looked exactly like the CBI but wonder how it would compare in person. It is actually bothering me because I want to make a 3 stone with my BGD and since they will be smaller side stones I want them to pack a punch, but would love to go with BGD again if they are in fact comparable.

 

[Double E]

Not sure if this also a question that many would like to be answered. But it is for me as I am picking my stone from BGD~

 

[MamaBee]

As a pretty new Pricescoper..I’m still trying to figure out the vendors because you use initials..I’ve figured out most but stumped with CBI. Who are they?

 

[tyty333]

CBI - Crafted by Infinity diamonds

HPD - High Performance Diamonds sells CBIs (hope that fills in the picture for you)

 

[MamaBee]

CBI - Crafted by Infinity diamonds

HPD - High Performance Diamonds sells CBIs (hope that fills in the picture for you)

Thanks!

 

[diamondseeker2006]

Superideal cut stones are going to be similar. They are all cut within a narrow range of measurements. Seriously, pick the stone that has the size, color, clarity you want within your budget.

Fire has to do with the lighting. You will see fire in some lighting more than others. Sometimes none.

Superideal cut stones are all great, so just choose the one that appeals to you most!

(In general, a smaller table and higher crown angle will have slightly more fire, but you likely won't be able to tell the difference since superideals are cut within such a narrow range.)

 

[diamondseeker2006]

I have been wondering the same. When watching the CBI, WF, and JA comparison videos that another user posted, I felt like my BGD looked exactly like the CBI but wonder how it would compare in person. It is actually bothering me because I want to make a 3 stone with my BGD and since they will be smaller side stones I want them to pack a punch, but would love to go with BGD again if they are in fact comparable.

The key with a three stone ring is to get side stones that are a close match to each other and fairly close to the center stone. But the main thing is that they have the same color, diameter, and a close table size to each other. It doesn't matter where you buy them as long as they are superideal cut. But I certainly would try BG first since that is where the center stone came from. (It would be a grave error to use one video to draw conclusions considering the three diamonds were not all identical at the outset, and you have no idea if they were even all cleaned to the same degree.)

 

[Texas Leaguer]

When you are comparing AGS0 Ideals with light performance based reports, remember that the AGS cut grading process involves ray tracing with 30,000 virtual light rays and evaluating fire specifically, along with brightness, contrast and leakage. Any appreciable deficit in fire will result in the diamond failing to make Ideal.

While even the ideal grade represents a small range of quality, it is a very high baseline. If you further enforce faceting precision criteria (super ideals), you don't have much to worry about with any of the light performance aspects.

Clarity features and to some extent color should become more of a focus in terms of realized light performance at this level of cut quality.

 

[BlingDreams]

Recently there was a thread looking into the potential difference of fire between CBI stones , and has been brought to the attention of fellow PSers. Thanks for John's extensive information, we are allowed for more insight into the topic.

This at the same time has created another question in my mind. With BGD being an equally reputable vendor, is there any difference of fire between stones within their top lines actually? Appreciated if any expert or experienced BGD clients could provide a better picture of this~

I wish it was a month from now and then I could give you a true comparison. I have BGD signature diamond earrings arriving late next week and should have my HPD/CBI diamond pendant in 3-4 weeks. If you remind me, say mid-September?, I’d be happy to make a video for you of the three stones side by side. The nice thing will be that they’ll all be close to the same size, color, and clarity.

 

[diamondseeker2006]

When you are comparing AGS0 Ideals with light performance based reports, remember that the AGS cut grading process involves ray tracing with 30,000 virtual light rays and evaluating fire specifically, along with brightness, contrast and leakage. Any appreciable deficit in fire will result in the diamond failing to make Ideal.

While even the ideal grade represents a small range of quality, it is a very high baseline. If you further enforce faceting precision criteria (super ideals), you don't have much to worry about with any of the light performance aspects.

Clarity features and to some extent color should become more of a focus in terms of realized light performance at this level of cut quality.

Bryan, I just need to start copying and saving your posts when things like this come up so I can quote you!

 

[Texas Leaguer]

Bryan, I just need to start copying and saving your posts when things like this come up so I can quote you!

You are too kind DS!

 

[Double E]

When you are comparing AGS0 Ideals with light performance based reports, remember that the AGS cut grading process involves ray tracing with 30,000 virtual light rays and evaluating fire specifically, along with brightness, contrast and leakage. Any appreciable deficit in fire will result in the diamond failing to make Ideal.

While even the ideal grade represents a small range of quality, it is a very high baseline. If you further enforce faceting precision criteria (super ideals), you don't have much to worry about with any of the light performance aspects.

Clarity features and to some extent color should become more of a focus in terms of realized light performance at this level of cut quality.

Thanks Bryan. May be we are just splitting hair here~But you know people who tend to choose super ideals tend to split hair sometimes When we get closer to a decision and got more options, we got more headach Appreciate professionals like you are able to educate the community~

 

[Double E]

I wish it was a month from now and then I could give you a true comparison. I have BGD signature diamond earrings arriving late next week and should have my HPD/CBI diamond pendant in 3-4 weeks. If you remind me, say mid-September?, I’d be happy to make a video for you of the three stones side by side. The nice thing will be that they’ll all be close to the same size, color, and clarity.

That's so kind of youI am sure many of us would definitely wish to have you share the video with us! I shall take a note to remind you later,hahaBtw, my wife will be surely jealous that you are having 3 super ideals at the same time!!

 

[sledge]

I'm always intrigued with what @Texas Leaguer has to say, as he is well spoken and smart. Thank you Bryan, for sharing your time & expertise with us, it is a better place with your contributions.

When trying to evaluate BGD stones, please keep in mind there are 3 main brands to be considered:

BGD Signature Series
The "standard" line of true H&A super ideals, limited to none or faint fluor.

https://www.briangavindiamonds.com/diamond/brian-gavins-hearts-and-arrows/


BGD Blue Series
Cut to the same standards as the Signature series but has medium+ fluor. Technically not marketed for their H&A symmetry but cut on the same lines, etc; therefore, they are typically (but not guaranteed) to be the same.

https://www.briangavindiamonds.com/news/brian-gavin-blue-vs-hearts-and-arrows/
https://www.briangavindiamonds.com/diamond/brian-gavins-blue-diamonds-with-fluorescence/


BGD Black Series
Advanced & unique cutting techniques that supersede Signature series for improved light performance. Most precise H&A pattern for exacting symmetry. Color requirements are G+ on stones < or = 2.9cts. Due to rarity of 3ct+ stones, lower colors may be used on these larger stones. Clarity requirements are minimum VS2+.

https://www.briangavindiamonds.com/news/black-brian-gavin-vs-brian-gavin-signature/
https://black.briangavindiamonds.com/

 

[sledge]

The above post in mind, I would expect to see BGD Signature & Blue series stones perform in a similar fashion. Because the H&A cutting technique is not marketed or monitored as closely on the Blue series, you might start to see some Signature series stones exhibiting better light performance than their Blue counterparts.

That said, the best results should be evident in the Black series. I have yet to see a Black series stone in-person but having seen various videos I would agree there is more sparkle to them.

 

[Dancing Fire]

I have seen 2 CBI (1.23ct & 1.25ct) and have had bought 3 BGD (.25ct -.75ct) and also saw my nephew's 1.18ct stone . All I will say is that they both sell top quality H&A stones. I'll purchase from either vendor depending on who has the 3Cs that I'm looking for. I pretty much know what to expect from these two top quality vendors.

I will soon get to see my first BG med blue stone.

 

[OoohShiny]

CBI do emphasise that the additional time spent nuancing facets creates improved light performance, but as already mentioned, all of the SuperIdeals are based around a similar set of angles etc., so they will all look great.

The CBI 'secret sauce' has been the subject of much debate, and it does seem that viewing in person is the only way to assess if it makes a difference to you personally, so I can't wait for @ILikeShiny's side-by-side assessment!

 

[sledge]

Without having an opportunity to put them side by side and see with my own eyes I am hesitant to say one is better than another.

From what I've read I think BGD Black would be most comparable to a CBI because of the additional time spent toying with facets. Both are proprietary and as such you may see a person prefer one or the other.

My point being we all have different preferences so what is best to one may not be best to another. And I think the differences are very minor, yet if our eyes love that particular preference you are likely hooked.

One small example is I prefer WF videos of stones. But really I wish there was a standard of sorts to view videos between different vendors so we could more equally compare as a consumer. I've looked at a lot of WF videos and can normally spot a small table of 54 to 55 with a crown near 34.5 and pavilion of 40.7 to 40.8. The stone appears more lively to me. I have no objective data for the reasoning. It's just what I prefer and I think all ACA's are gorgeous but if I have an opportunity to snag one with those specs I would do so.

Personally I'd love to have all WF, BGD and HPD stones together to see in-person. Have them situated blindly and let us choose our preference. It would be a tough choice I think.

 

[Wewechew]

Without having an opportunity to put them side by side and see with my own eyes I am hesitant to say one is better than another.

From what I've read I think BGD Black would be most comparable to a CBI because of the additional time spent toying with facets. Both are proprietary and as such you may see a person prefer one or the other.

My point being we all have different preferences so what is best to one may not be best to another. And I think the differences are very minor, yet if our eyes love that particular preference you are likely hooked.

One small example is I prefer WF videos of stones. But really I wish there was a standard of sorts to view videos between different vendors so we could more equally compare as a consumer. I've looked at a lot of WF videos and can normally spot a small table of 54 to 55 with a crown near 34.5 and pavilion of 40.7 to 40.8. The stone appears more lively to me. I have no objective data for the reasoning. It's just what I prefer and I think all ACA's are gorgeous but if I have an opportunity to snag one with those specs I would do so.

Personally I'd love to have all WF, BGD and HPD stones together to see in-person. Have them situated blindly and let us choose our preference. It would be a tough choice I think.

So I purchased a BG Black when they first came out. I ended up liking my ACA better and sent it back. It could be that I liked the angles better on my ACA, but I was a bit disappointed.

 

[sledge]

So I purchased a BG Black when they first came out. I ended up liking my ACA better and sent it back. It could be that I liked the angles better on my ACA, but I was a bit disappointed.

Care to share tech data on each stone, or the certs. I'm curious myself.

 

[Wewechew]

Care to share tech data on each stone, or the certs. I'm curious myself.

https://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3735100.htm

https://www.briangavindiamonds.com/.../0.604-e-vs2-round-diamond-bkags-104090535055

 

[lovedogs]

Without having an opportunity to put them side by side and see with my own eyes I am hesitant to say one is better than another.

From what I've read I think BGD Black would be most comparable to a CBI because of the additional time spent toying with facets. Both are proprietary and as such you may see a person prefer one or the other.

My point being we all have different preferences so what is best to one may not be best to another. And I think the differences are very minor, yet if our eyes love that particular preference you are likely hooked.

One small example is I prefer WF videos of stones. But really I wish there was a standard of sorts to view videos between different vendors so we could more equally compare as a consumer. I've looked at a lot of WF videos and can normally spot a small table of 54 to 55 with a crown near 34.5 and pavilion of 40.7 to 40.8. The stone appears more lively to me. I have no objective data for the reasoning. It's just what I prefer and I think all ACA's are gorgeous but if I have an opportunity to snag one with those specs I would do so.

Personally I'd love to have all WF, BGD and HPD stones together to see in-person. Have them situated blindly and let us choose our preference. It would be a tough choice I think.

This would be a dream come true!

 

[FL_Sol]

https://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3735100.htm

https://www.briangavindiamonds.com/.../0.604-e-vs2-round-diamond-bkags-104090535055

Do you think it is the lower girdle facets that drew you in? Or more than that? Mine has the same as the WF, 76 and I love it. They BGD one you returned has 78. I feel like the arrows just flash so strongly and make the diamond so noticeable.

 

[Texas Leaguer]

Without having an opportunity to put them side by side and see with my own eyes I am hesitant to say one is better than another.

From what I've read I think BGD Black would be most comparable to a CBI because of the additional time spent toying with facets. Both are proprietary and as such you may see a person prefer one or the other.

My point being we all have different preferences so what is best to one may not be best to another. And I think the differences are very minor, yet if our eyes love that particular preference you are likely hooked.

One small example is I prefer WF videos of stones. But really I wish there was a standard of sorts to view videos between different vendors so we could more equally compare as a consumer. I've looked at a lot of WF videos and can normally spot a small table of 54 to 55 with a crown near 34.5 and pavilion of 40.7 to 40.8. The stone appears more lively to me. I have no objective data for the reasoning. It's just what I prefer and I think all ACA's are gorgeous but if I have an opportunity to snag one with those specs I would do so.

Personally I'd love to have all WF, BGD and HPD stones together to see in-person. Have them situated blindly and let us choose our preference. It would be a tough choice I think.

Sledge,
I think you are quite correct that for a buyer with a keen eye, there are 'taste' options even in the super-ideal realm, and even within individual brands of super-ideals.

And thank you for your nice comments!

 

[Wewechew]

Do you think it is the lower girdle facets that drew you in? Or more than that? Mine has the same as the WF, 76 and I love it. They BGD one you returned has 78. I feel like the arrows just flash so strongly and make the diamond so noticeable.

I think it's either that, or the slightly bigger table. The WF stone was bright all the time, even in a dimly lit hallway.

 

[Dancing Fire]

Personally I'd love to have all WF, BGD and HPD stones together to see in-person. Have them situated blindly and let us choose our preference. It would be a tough choice I think.

Do a gent's 3ct three stone ring. A 1ct stone from each vendor.

 

[Double E]

Do a 3ct three stone ring. A 1ct stone from each vendor.

Would really hope someone does that one day!

 

[Dancing Fire]

Would really hope someone does that one day!

Yup, A gent's 3 stone ring!

 

[sledge]

https://www.whiteflash.com/loose-diamonds/round-cut-loose-diamond-3735100.htm

https://www.briangavindiamonds.com/.../0.604-e-vs2-round-diamond-bkags-104090535055

Do you think it is the lower girdle facets that drew you in? Or more than that? Mine has the same as the WF, 76 and I love it. They BGD one you returned has 78. I feel like the arrows just flash so strongly and make the diamond so noticeable.

I think it's either that, or the slightly bigger table. The WF stone was bright all the time, even in a dimly lit hallway.

Thank you for sharing the additional information @Wewechew. Before we get too much further, both are gorgeous stones and I am glad you got the opportunity to see both close up.

I didn't start studying diamonds until a few months back, so I feel my resources and ability to explain what I am thinking is fairly limited. I will do the best I can with my limited knowledge. In short everything works together (CA, PA, table, depths, star facets & LGF's). While many factors are very close, you are starting to see minor changes in multiple areas that are combining to create one stone that you found visually appealing and the other you didn't.

Here is what I have noticed:

• Crown angle = 34.7 both
• Crown thickness = 15.3 WF | 15.7 BGD
• Table = 55.8 WF | 54.6 BGD

With the WF table being larger and the CA remaining the same the crown thickness is forced to change to a lower value. However, this slightly changes the facets as well.

This led me down a rabbit hole where I started building simplistic 2D models in my CAD program. Below are some screen captures which led me to some more points I found interesting.

• BGD stone measures 5.42 x 5.44 x 3.36. Additionally the cert indicates a depth of 61.9%. Having a non-perfect round, I checked both measurements:
  • 3.36 / 5.42 = 0.619926199, or 62.0% rounded appropriately
  • 3.36 / 5.44 = 0.617647059, or 61.8%
  • 3.36 / 5.43 (avg) = 0.61878453, or 61.9% - Okay, seems reasonable
• WF stone measures 4.77 x 4.79 x 2.96. Depth is reported at 61.8%. Again, more math:
  • 2.96 / 4.78 (avg, having learned the lesson already) = 0.619246862, or 62.0%
  • 2.96 / 4.77 = 0.620545073, or 62.1% (makes sense, divide same # by smaller #)
  • 2.96 / 4.79 = 0.617954071, or 61.8%
• Seems I'd use the average, high or low value on both stones instead of the average on BGD and high on WF. Of course, AGS probably measured with a Sarin machine and rounded that value as well.
• In a theoretical world, neither model produced an EXACT cutlet point using the size, depth % and angles reported. However, WF was closer.
• What I found interesting is that the 40.76 degree angle I discovered is the EXACT angle where the cutlet shown on the ASET turns red or green. Neither is necessarily better or worse, just a matter of how the light refracts back at a certain color because of a small change in angle. If you look at the actual WF ASET image, you will see where most of it is green, but some is red.
• Oddly enough, the exact angle to form a cutlet on the BGD stone was 40.7 (despite reported pavilion of 40.9) which falls below the 40.76 division line and makes the cutlet appear green in the ASET.
• My model is glorified chicken scratch in comparison to the tools WF & BGD have, so I am not trying to make any final conclusions. I just noted these as oddities and points of interest to me.

https://www.whiteflash.com/about-di...n/aset---table-reflection-whiteflash-1420.htm





Moving on.

• LGF's = 76 WF | 78 BGD
• Star Facets = 53 WF | 52 BGD

Differences between the LGF's seem minor but many people tend to favor "fat arrows" which come from 75-76 LGF's. Looking at still photos, you can see the arrow difference between the two stones. WF actually has a good write-up on this. The examples used in the beginning are more extreme (75/80/85) but towards the end they end up comparing closer facets (78/80/82).

In short, lower LGF's perform better with less lighting and larger LGF's perform better in brighter lighting environments. The differences are minimal and there are minor trade-off's with both. Other characteristics come into play but generally speaking a 75-80 LGF is "good".

https://www.whiteflash.com/about-diamonds/diamond-education/facets-the-lower-halves.htm

Based on all this I think the 76 LGF in combination with other minor factors made a difference in your viewing/preference of the two stones.

Also, here is some good information how star facets can play into the equation as well. Again, minor but really at this level we are about nitpicking anyhow, so I am going to throw it out there. I haven't personally compared star facets and won't comment much other than to say it seems to me very negligible with a 52/53 value.

https://www.prosumerdiamonds.com/star-facet/