will i get more sparkle with a prong set stone compared...

[Dancing Fire]

to a bezel set? because the prong set would expose the girdle,then i should get more sparkles ?

 

[valeria101]

I don't think diamonds sparkle from underneath... at all.

ever seen an I-scope pic of a diamond bottom-up ?!

 

[Dancing Fire]

----------------
On 7/6/2004 7:38:19 PM valeria101 wrote:


I don't think diamonds sparkle from underneath... at all.

ever seen an I-scope pic of a diamond bottom-up ?!




----------------

Valeria
i meant on the edge of the stone

 

[Magnum]

Since your stone is ideal cut, I would say probably not a noticeable amount more sparkles. In an ideal cut stone almost all of the light that enters the top of the stop comes back out the top of the stone, which is one of the reasons why it's "ideal". In some more mediocre cut stones there is a lot more light leakage, which means that more light that goes into the top of the stone goes out the bottom, instead. However, the converse is also true in both cases. In an ideal cut stone, very little light that enters the bottom of the stone will come out the top, whereas in a non-ideal stone with a lot more light leakage, more light that enters the bottom of the stone will exit the top. That's the reason why it's sometimes recommended that if you have a stone with more than average light leakage, it's probably a good idea to get as open a setting as possible to allow more light to enter the bottom, and hence, create more sparkles coming out of the top. In an ideal cut stone, there is so little light leakage that I doubt you'd notice any difference in the two types of settings. I had an AGS0 H&A stone with excellent light return set in a bezel setting, and I don't notice any difference in the sparkle from when the stone was loose, before it was set.

 

[valeria101]

I know, I know... but I just like bezels

I think the whole idea of the ideal cut is that light coming from above turns back - all that red under the Iscope is just that. A bezel will go over the diamond just as much as a prong, but will stop light entering from around the stone - something important for some cuts, but not the RBC.

Most rounds - ideal or not - will not reflect light down to the edge of the girdle. Some would, due to a special cut intended to make the Iscope red edge to edge. Now, how could that tiny stripe around the diamond make a huge loss of brilliance ?

 

[Magnum]

I would think that light entering the girdle has such a small effect on the amount of light coming out the top of the stone, that it would be a significantly smaller factor than even the small effect of light coming in the bottom of an ideal cut stone that I already talked about. For one, I don't have any ray tracing at the tips of my fingers, but I think that most light entering sideways would just go out the other side. And even if it did get reflected up, the surface area of the girdle is so small that it still wouldn't be noticeable.

 

[valeria101]

Would THIS help ?

I think this piece of graphics shows a thick ray ( = "beam"?) going in through an upper girdle facet and getting out through another. The demonstrative ray is placed just so (at a small angle relative to the pavilion main) not to get lost. Meaning (I hope) that getting light through the girdle does not do anything impressive to the rest of the diamond. This is good, since the same logic insures that not much light gets lost due to a thick girdle.

I wish I saw the same dome with a Regent, given that the setting advice required the thick girdle facets to remain free.

 

[chrono]

I've read about the Regent needing to be set as openly as possible to maximize the sparkle due to its cut. Does a Jubilee need to be prong set too? Will it sparkle less in a bezel setting since it looks like the Iscope reading shows red from edge to edge?

 

[Garry H (Cut Nut)]

True - diamonds like the modified rounds turned square have very large girdle facets and these act as additionla facets.

I believe now that setting diamonds so light can get in the back helps with fire. This idea has been growing on me for about 1 year.

 

[verticalhorizon]

A turn in the tide?

I had heard or read that a properly cut diamond will reflect all of it's light that comes in through the crown, right back out of the crown, so it wouldn't matter if it's prong set or bezel set.

Under this premise, a bezel setting would most certainly effect a retail grade cut diamond.

 

[Brian Knox]

Hi,

There is no question in my mind that a diamond shows more brilliance in a prong setting compared to a bezel setting.

There is simply more light allowed into the diamond.

 

[Dancing Fire]

----------------
On 7/8/2004 8:40:15 AM Garry H (Cut Nut) wrote:

True - diamonds like the modified rounds turned square have very large girdle facets and these act as additionla facets.

I believe now that setting diamonds so light can get in the back helps with fire. This idea has been growing on me for about 1 year.----------------

cutnut,
so, a prong setting with an open pavil would help a rb to get more fire?

 

[mm]

A poorly cut diamond is one that does not have the correct angles to reflect light entering through the top of the stone back through the top of the stone.

Presumably, however, if you allow light in from more angles that the top (ie claw setting rather than bezel setting) you have more chance of those "incorrect angles" reflecting the light up through the top of the stone.

If that correct?

 

[Garry H (Cut Nut)]

mm yes - the worse the cut the more the advantage, but remember that even the best cut only returns 73.2675% of light from above (that is a joke).

 

[mm]

I guess I was actually thinking more for princess cuts etc- which don't return light anywhere near as well as RBs (probably not even 73.2675435271%)

.

So presumably even a well cut princess would benefit from having a more exposed setting?

 

[amateur]

Date: 7/6/2004 7:59:34 PM
Author: Magnum
Since your stone is ideal cut, I would say probably not a noticeable amount more sparkles. In an ideal cut stone almost all of the light that enters the top of the stop comes back out the top of the stone, which is one of the reasons why it''s ''ideal''. In some more mediocre cut stones there is a lot more light leakage, which means that more light that goes into the top of the stone goes out the bottom, instead. However, the converse is also true in both cases. In an ideal cut stone, very little light that enters the bottom of the stone will come out the top, whereas in a non-ideal stone with a lot more light leakage, more light that enters the bottom of the stone will exit the top. That''s the reason why it''s sometimes recommended that if you have a stone with more than average light leakage, it''s probably a good idea to get as open a setting as possible to allow more light to enter the bottom, and hence, create more sparkles coming out of the top. In an ideal cut stone, there is so little light leakage that I doubt you''d notice any difference in the two types of settings. I had an AGS0 H&A stone with excellent light return set in a bezel setting, and I don''t notice any difference in the sparkle from when the stone was loose, before it was set.

I wonder if this logic applies to other stone cuts w/ more light leakage, i.e. Emerald/Asscher cuts? Is it better to set Emerald & Asscher cuts in a very open setting since they probably have much less brilliance from the top?

 

[Garry H (Cut Nut)]

Yes, a small benefit for prongs when the stone is a well cut round, and a much bigger benefit from a leaky fancy cut stone

 

[PhillipSchmidt]

This is all very interesting for me. I have always thought it does, because that is what I see, but I can see how the better cuts are less affected.

The thing for me, is that bezel set diamonds get dirty easier and that grime, (perhaps also cuppled with the affect of no light) makes a big difference. You certainly, must clean a bezel set diamond more often.

Would it be fair to say that a grimy stone is less afected in cases where there is some light reaching the cutlet?

Just a thought,

PS