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Why can’t pear diamonds be optimized for light return too?

OMG, it's the Clash of the Titans. I love this. How am I going to afford to buy a diamond from each of these gentlemen?
I just came on to say I saw an antique pear on ebay, described as from the 1930s. If anyone is interested, I can look for a link.
 
Ibrakeforpossums said:
OMG, it's the Clash of the Titans. I love this. How am I going to afford to buy a diamond from each of these gentlemen?
I just came on to say I saw an antique pear on ebay, described as from the 1930s. If anyone is interested, I can look for a link.
Click to expand...

Oh my goodness! Tempting indeed...I already bought "tester" cz pear studs to try on for sizing! :lol:

But it is totally outta the question for me for now...I am closing on a house and am absolutely out of the game on diamond purchases for a bit...but ooooh hope someone snags the one you found and shares back here!
 
It is an interesting, and never solvable debate.
I appreciate science- and specifically the science of analyzing light, and how it impacts the cutting of diamonds.
Yet the data it provides isn't always relevant. It's possible to rely on metrics that are scientific, yet may not address your specific considerations in real life.
I've long abandoned my failed crusade to address the inaccuracies in nomenclature. The word "Leakage" is a great example.
Leakage has to be bad right?
Anyway, don't get me started.
 
Rockdiamond said:
It is an interesting, and never solvable debate.
I appreciate science- and specifically the science of analyzing light, and how it impacts the cutting of diamonds.
Yet the data it provides isn't always relevant. It's possible to rely on metrics that are scientific, yet may not address your specific considerations in real life.
I've long abandoned my failed crusade to address the inaccuracies in nomenclature. The word "Leakage" is a great example.
Leakage has to be bad right?
Anyway, don't get me started.
Click to expand...

I love this.
 
It is possible to create a bright diamond with good scientific performance that absolutely fails at the one thing it should excel at and that is looking like a pear cut.
Getting a bright lively body with a bright lively point should be the goal.
One without the other is not visually a pear cut in many lighting conditions.
 
Karl_K said:
It is possible to create a bright diamond with good scientific performance that absolutely fails at the one thing it should excel at and that is looking like a pear cut.
Getting a bright lively body with a bright lively point should be the goal.
One without the other is not visually a pear cut in many lighting conditions.
Click to expand...
I beg to slightly differ Karl,
Vera has been wearing an oval for bout a month and I have fallen in love with the pinfire at the ends some of the time and the broad flashes through the (no bowtie) middle.
 
Loving this perfect pear conversation. I actually have a .41 antique pear pendant arriving soon from OWD. I’m going to look at it in a different light after learning so much on this pear thread :)
 
caolsen said:
Loving this perfect pear conversation. I actually have a .41 antique pear pendant arriving soon from OWD. I’m going to look at it in a different light after learning so much on this pear thread :)
Click to expand...

Did you snag that gorgeous pendant they had on IG?
 
diagem said:
This Aset doesnt look itself, does it?
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Hey compadre,

The ASET depicted in that scan is dead on accurate. I have the actual ASET photograph on some hard drive but I can verify, what you see there is spot on. About 95% windows. o_O
 
Garry H (Cut Nut) said:
I beg to slightly differ Karl,
Vera has been wearing an oval for bout a month and I have fallen in love with the pinfire at the ends some of the time and the broad flashes through the (no bowtie) middle.
Click to expand...

I agree.
I just had a five stone pear ring made. My 2ct pear ctr has pinfire flashes at ends and alot of broad flashes in center area... so enjoyable watching it dance... I'm in love.
 
Rhino said:
Hey compadre,

The ASET depicted in that scan is dead on accurate. I have the actual ASET photograph on some hard drive but I can verify, what you see there is spot on. About 95% windows. o_O
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Still doesnt seem itself..., have seen plenty such flat cuts and their ASET's look quite different..., If you are able.., would love to see the actual ASET. I am missing some facets junctions and partial leakage spots..., way to white with no information. Sorry.
 
diagem said:
Still doesnt seem itself..., have seen plenty such flat cuts and their ASET's look quite different..., If you are able.., would love to see the actual ASET. I am missing some facets junctions and partial leakage spots..., way to white with no information. Sorry.
Click to expand...

it's on some hard drive somewhere but I never ever forgot it because it was one of the worse ASET results I ever saw and an AGS 10 out of 10. I had it in a video on my prior YouTube channel but someone saw fit to pull it off the Internet. :knockout: It was a good educational clip too. When my eyes and tech are in full agreement my friend, I don't unique instances as this.
 
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Rhino said:
it's on some hard drive somewhere but I never ever forgot it because it was one of the worse ASET results I ever saw and an AGS 10 out of 10. I had it in a video on my prior YouTube channel but someone saw fit to pull it off the Internet. :knockout: It was a good educational clip too. When my eyes and tech are in full agreement my friend, I don't unique instances as this.
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Ok..., not a round but nonetheless a very similarly cut flat Old Mine Pear that I still have the info...

See what I mean (while the pear has even shallower facets than 27°) by a representative ASET should look very different than what you demonstrated.

3.36ctOPM_FLAT_VS_RB.jpg
 
diagem said:
Ok..., not a round but nonetheless a very similarly cut flat Old Mine Pear that I still have the info...

See what I mean (while the pear has even shallower facets than 27°) by a representative ASET should look very different than what you demonstrated.

3.36ctOPM_FLAT_VS_RB.jpg
Click to expand...

24.5 degrees is the critical angle and one facet is under that (plus the culet).
The Sarine ASET to the left is not I believe accurate?
 
Garry H (Cut Nut) said:
24.5 degrees is the critical angle and one facet is under that (plus the culet).
The Sarine ASET to the left is not I believe accurate?
Click to expand...

Exactly, and the pavilion facet angles reaching the shoulders and rounded tip are somewhere in-between and are clearly showing the effect I call partial leakage. Which is never white (transparent).
 
Garry H (Cut Nut) said:
24.5 degrees is the critical angle and one facet is under that (plus the culet).
The Sarine ASET to the left is not I believe accurate?
Click to expand...

There is never any leakage that is total. It is always partial and there is no leakage untill the internal angle is 24.5 from the internal normal. Or 90 minus 24.5 Yoram.
 
Garry H (Cut Nut) said:
There is never any leakage that is total. It is always partial and there is no leakage untill the internal angle is 24.5 from the internal normal. Or 90 minus 24.5 Yoram.
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Garry, an open culet parallel to the table will always display total leakage until the diamond is slightly tilted and an optical effect occurs. (see example in my avatar).

Many times this "partial leakage" is also derived from light entering just below the girdle which is completely opposed to current laboratories modus operandi which states light comes from above only (above girdle for grading sakes).

When we want to be fair with grading diamond's handling of lights as per light performance standards, I believe we need to consider all directions of lights and not just upper hemisphere.
 
diagem said:
Garry, an open culet parallel to the table will always display total leakage until the diamond is slightly tilted and an optical effect occurs. (see example in my avatar).

Many times this "partial leakage" is also derived from light entering just below the girdle which is completely opposed to current laboratories modus operandi which states light comes from above only (above girdle for grading sakes).

When we want to be fair with grading diamond's handling of lights as per light performance standards, I believe we need to consider all directions of lights and not just upper hemisphere.
Click to expand...
Actually Yoram the amount of tilt is not slight. Even the Kozobie effect results in culet leakage.
I am not a fan of below the girdle light sourcing because one never knows how a diamond will be set and the typical gunk pavilion side.
I will try to demonstrate with the original scan of the Kohinoor plaster > lead cast - your avatar. But it has a million facets and DiamCalc takes an hour per image.
1640126763980.png
 
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Rhino said:
Load it up. ASET white is *always* the best for examining leakage.
Click to expand...
only if in some cases you consider less than 10%-15% of the virtual facets in an area drawing light from the pavilion as total leakage.
ASET white has very bad virtual facet resolution.
ASET black has the same issue but a little more resolution when it comes to virtual facets drawing light from the pavilion.
Which is different and more common than leakage like a window.
 
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