Does a bezel setting change and/or decrease light return?

[blueiris]

I have a diamond pendant that is set in a bezel setting with the little loops. I'll attempt to attach a photo of this setting from Blue Nile. I don't have a photo of this setting from the side but it is open at the back and has a channel cut around the middle of the bezel so some light does get in. It's a fairly deep setting, a little deeper than my diamond (1.37 ct.)

I've noticed that though this pendant looks really bright when I look in the mirror, I don't seem to get as much fire or scintillation as I do from my ring, even when it's not on my neck (i.e., when I'm holding it in various lighting situations). I'm wondering if perhaps the pendant's setting is hampering light return, since there is just a thin channel cut in the bezel mounting? I don't know enough about how exposure of the pavilion affects light performance.

When I'm wearing it and look in the mirror, I also wonder if perhaps the fixed setting (i.e., it doesn't slide back and forth as it would if it was in a mounting with a bail that slides along the chain) is one reason I don't see as much fire, etc., because it's not moving much while being worn. It pretty much stays put in the center, which is nice unless it's making my diamond look less sparkly.

I don't think the perceived lack of fire and scintillation is because of the diamond. I hadn't remembered about Pricescope when my husband purchased this diamond for me, but after I started looking for a new diamond for my ring and remembered Pricescope, I put the pendant diamond's numbers in the HCA and it scored very well (.9, if I remember). It's a beautiful diamond from Blue Nile's Signature line.

My question is if the setting could be affecting the light return - would exposing the pavilion more help? Thanks for any help!

 

[Garry H (Cut Nut)]

Re: Does a bezel setting change and/or decrease light return

try holding your ring in the exact same position as the pendant and i will bet you find it is because of the lighting when you are facing the mirror

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

blueirs- a bezel is a compromise- any setting is.
With a bezel you gain some sleekness- and a lovely look, but the cost is a bit of brightness as light can't enter through the girdle.

 

[slg47]

Re: Does a bezel setting change and/or decrease light return

with well cut stones, most of the light reflected is entering from the top, so a bezel will not significantly affect light performance.

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

Given that many discussions on this site revolve around minute differences in brilliance, I think it's safe to say that there is a difference in brilliance between prong and bezel setting.
It might be small, but I believe it will be perceptible.
The quality of cut will not mitigate this.

 

[stone-cold11]

Re: Does a bezel setting change and/or decrease light return

No, it shouldn't. Try the test of Garry.

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

Interesting- how would totally blocking the girdle of a diamond not affect how much light is coming out?

 

[stone-cold11]

Re: Does a bezel setting change and/or decrease light return

Unless the performance of your stone is strongly dependent on light coming in from that direction, aka leakage, most of the light return by it will be from the crown, which the reflector technology shows.

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

Most being the key word here- not all,.
The girdle, and it's ability to gather light will affect the way a diamond looks.
It's kind of ironic to read what you're writing Stone- when a diamond has .00001% difference in angle, you scream it's going to leak, but now you're saying that if you entirely block off one of the most important areas of the diamond..... viola!- no difference.

 

[Garry H (Cut Nut)]

Re: Does a bezel setting change and/or decrease light return

Most being the key word here- not all,.
The girdle, and it's ability to gather light will affect the way a diamond looks.
It's kind of ironic to read what you're writing Stone- when a diamond has .00001% difference in angle, you scream it's going to leak, but now you're saying that if you entirely block off one of the most important areas of the diamond..... viola!- no difference.

What evidence do you have to support that claim RD?
I would agree that it would be important in the case of a fish eye. But I am not convinced in the case of a well cut stone. Also there is a thing that all researchers have applied called 'weighting' which assumes most light (and most views) comes fro directly above the diamond, and a lot less from the sides.

 

[stone-cold11]

Re: Does a bezel setting change and/or decrease light return

I guess you still do not understand what reflector technology shows.

No point talking, just beating about the same bush over and over again.

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

Garry- as you say "weighting" assumes most light comes directly from above- I would disagree with that statement based on actual physical properties. The only way to truly block off the light coming into the side of a diamond is...well, bezel set it.

The evidence I have is my experience. We've set many thousands of diamonds, quite a few in bezels.
Bezel setting can be beautiful- but it does change the way a diamond handles the light- if even slightly. This is what I tell folks asking for bezels, as it's been my experience.
But I do find it rather unbelievable that anyone could argue that closing a girdle to all light will have no perceptible effect.

 

[LGK]

Re: Does a bezel setting change and/or decrease light return

I reset my OEC into a bezel, from a prong setting. No change in performance whatsoever. (it faces up whiter, but I think that's a lack of sidestones thing, not a bezel thing.) It is well cut. A poorly cut stone may have a change in performance due to a bezel but not a stone that is returning light well.

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

I reset my OEC into a bezel, from a prong setting. No change in performance whatsoever. (it faces up whiter, but I think that's a lack of sidestones thing, not a bezel thing.) It is well cut. A poorly cut stone may have a change in performance due to a bezel but not a stone that is returning light well.

How can it "face up whiter"- but have no change in performance?
This is not about how well cut a stone is.
A well cut stone gathers light from the girdle as well.
A thick girdled stone- or a fish eye- may show more difference, but there will be a difference regardless of the cut.

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

Little grey- sorry I typed a little fast- didn't mean to sound harsh.

For a true comparison, we'd need to have the same stone set differently and compare it- which is physically impossible. We can only go on our memory.

Physics dictates that blocking off part of a diamond- even the bottom- changes the way light moves through it.

 

[Garry H (Cut Nut)]

Re: Does a bezel setting change and/or decrease light return

I reset my OEC into a bezel, from a prong setting. No change in performance whatsoever. (it faces up whiter, but I think that's a lack of sidestones thing, not a bezel thing.) It is well cut. A poorly cut stone may have a change in performance due to a bezel but not a stone that is returning light well.

How can it "face up whiter"- but have no change in performance?
This is not about how well cut a stone is.
A well cut stone gathers light from the girdle as well.
A thick girdled stone- or a fish eye- may show more difference, but there will be a difference regardless of the cut.

In order from the top left - the default tolkowsky with 57% table, top right, GIA thick girdle, bottom right 60% table 40% pavilion depth fish eye and lower left is a RD 60:60 nedium girdle.

None of these amounts of light are enough to make much diference in a monoscopic face up view.

If you rotate the stones then the fishe eye and the thick girdle start to show a bit more areas bright enough to possibly show up.

 

[stone-cold11]

Re: Does a bezel setting change and/or decrease light return

Physics dictates that blocking off part of a diamond- even the bottom- changes the way light moves through it.

Ya, physics, for someone who does not understand idealscope/ASET to talk about physics.

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

I'll admit I have no idea what you're saying Garry- but it does not change the fact - the answer to the OP's question is yes. We might be splitting hairs as to how much difference- I agree, if done well, a bezel won't change the appearance a great deal- but there will be a difference.

Of course we also need to take into account the quality of bezel work. The best bezel will have less effect than a really thick one- but there'll be some difference in any event.


Stone- please show me the physics books you're looking at.

 

[LGK]

Re: Does a bezel setting change and/or decrease light return

Little grey- sorry I typed a little fast- didn't mean to sound harsh.

For a true comparison, we'd need to have the same stone set differently and compare it- which is physically impossible. We can only go on our memory.

Physics dictates that blocking off part of a diamond- even the bottom- changes the way light moves through it.

No worries The whiter face up color is not really related to the bezel I don't think- it's the fact that it used to have contrasting side stones, and it doesn't anymore; not sure if that's the reason for the face up color difference between the two settings, but I think it is. But no visible change in performance, really... maybe it makes some sort of minute difference, but visibly- not at all. Just what I've observed, of course.

(And yeah- the bezel is super, super thin- very finely made, it's secure but covers just the tiniest amount of the stone. And don't forget- OECs = bruted girdle unless they've been recut, so no light coming in from there.)

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

Here's something I think applies: We've had a few antique stones lately- or at least, older looking stones with some abrasions around the girdle.
We had a cutter clean up the stones- and in doing so he gave them polished girdles- before that the girdles were "bruted" ( frosted looking)

I noticed a difference in brilliance- how could it not?

Contrasting side diamonds certainly affect the way a stone looks ( perception wise).
But to really test this, we'd need the same stone to be in two settings at once.

However it seems pretty simply to me- block off such a substantial part of a stone and it changes the amount of light going in- and the amount coming out.

 

[yssie]

Re: Does a bezel setting change and/or decrease light return

IF it is assumed true that not even superideals get and return 100% light from the top/crown (I make this assumption) then obviously enclosing the pavilion on any diamond and removing that additional source of incident light - superideal or not - is doing the stone no favours from the numerical point of light return. But in a well-cut diamond I do believe the effects to be negligible

 

[Garry H (Cut Nut)]

Re: Does a bezel setting change and/or decrease light return

I reset my OEC into a bezel, from a prong setting. No change in performance whatsoever. (it faces up whiter, but I think that's a lack of sidestones thing, not a bezel thing.) It is well cut. A poorly cut stone may have a change in performance due to a bezel but not a stone that is returning light well.

How can it "face up whiter"- but have no change in performance?
This is not about how well cut a stone is.
A well cut stone gathers light from the girdle as well.
A thick girdled stone- or a fish eye- may show more difference, but there will be a difference regardless of the cut.

In order from the top left - the default tolkowsky with 57% table, top right, GIA thick girdle, bottom right 60% table 40% pavilion depth fish eye and lower left is a RD 60:60 nedium girdle.

None of these amounts of light are enough to make much diference in a monoscopic face up view.

If you rotate the stones then the fishe eye and the thick girdle start to show a bit more areas bright enough to possibly show up.

Sorry - the image did not upload (dumb operator on new system)

 

[stone-cold11]

Re: Does a bezel setting change and/or decrease light return

Since you do not believe in what an idealscope is showing you is the light return, which is based on simple physics, what is there to say.

In an idealscope, there is a clear separation between light source from the pavilion, the white back lighting, and the light coming in from the direction of the viewer, red and black. Proper use of idealscope is to place the girdle just at the opening of the scope, meaning the red cone of the scope is above the girdle, so all the red light you see in the image are return from the top. How much white is there in a well cut stone then? How can you say that small amount white, most of it confined near the girdle, will cause a significant change in light performance?

I guess with your leaky stones, which is required for color stones, those will be significant which colors your opinion on the effect of bezels.

 

[Rockdiamond]

Re: Does a bezel setting change and/or decrease light return

Stone- we could make every question relate to Ideal Scope- then you can insult us needlessly, but that really misses the point- that being trying to assist people who come to ask questions- I honestly believe we both want to do that in such a way that assists the people asking.

Back to the question at hand:
I agree that some shapes, and types of cut are more affected by bezels. But I also have found that any round diamond, no matter how well cut, has some effect from a bezel.
There's another aspect to this- a bezel is not 1mm tall- it's generally taller- meaning that besides blocking the girdle, it will also block part of the pavilion- or even most of the pavilion.
Again, this may not prove to induce a dramatic difference from prong setting, but there will be some loss of light.

 

[Karl_K]

Re: Does a bezel setting change and/or decrease light return

It is very easy to test this yourself,,, take a bit of dark cardstock and cut it so it fits around the diamond.... vola removable bezel
There is for all practical purposes no difference face up in a well cut round.

From about a 30 degree angle there is a bit of difference if the diamond has a low crown height.
A 60/60 with a low crown will be much more effected than a fic even if they are equally well cut.
This comes from the bezel blocking light entering the upper girdles mostly.
The small upper girdles on a low crown height stone are effected more because a larger percentage is blocked.

 

[Karl_K]

Re: Does a bezel setting change and/or decrease light return

A bezel can ruin the looks of stones with under table leakage it does not even take a lot of leakage because it creates dead zones.
A well cut Round does not need the pavilion light.

 

[yssie]

Re: Does a bezel setting change and/or decrease light return

so Karl the worst diamond for a bezel is one with a large table, shallow crown, and long stars.?

ETA: and a well-cut FIC is spared b/c A) larger upper girdle facet area by virtue of the larger crown area resulting from higher crown and smaller table B) steeper crown angle allows upper girdle facets to rise above the rim of the bezel and intake light from a larger variety of angles

 

[Karl_K]

Re: Does a bezel setting change and/or decrease light return

so Karl the worst diamond for a bezel is one with a large table, shallow crown, and long stars.?

no the worst is one with large zones of under table leakage.
large table, shallow crown, and long stars would only have an effect when it is tilted around 30 degrees or so.

 

[stone-cold11]

Re: Does a bezel setting change and/or decrease light return

Stone- we could make every question relate to Ideal Scope- then you can insult us needlessly, but that really misses the point- that being trying to assist people who come to ask questions- I honestly believe we both want to do that in such a way that assists the people asking.

And who started the insults first? If you want people to play nice, stop the insults first.

 

[yssie]

Re: Does a bezel setting change and/or decrease light return

so Karl the worst diamond for a bezel is one with a large table, shallow crown, and long stars.?

no the worst is one with large zones of under table leakage.
large table, shallow crown, and long stars would only have an effect when it is tilted around 30 degrees or so.

i see
thanks!