Table 54 to 58 vs 59

[marrduk24]

All

As many of you know I was recently looking for a 3.5 to 4 carat diamond.

While researching one of the things I found was that a disproportionate number of diamonds in this size range had table > 58.

Eg when I recently looked at one of the sites, there were 5 diamonds when I capped table at 58 (and had bunch of other filters on proportions, color and carat). But the moment I increased table to 59, there were 13 diamonds. So it more than doubled the number of options.

This made me wonder what are the trade-offs associated with going to 59 table in this size range, assuming all other proportions were in the tight range (ie HCA < 2). Any inputs would be great.

 

[jp201845]

All

As many of you know I was recently looking for a 3.5 to 4 carat diamond.

While researching one of the things I found was that a disproportionate number of diamonds in this size range had table > 58.

Eg when I recently looked at one of the sites, there were 5 diamonds when I capped table at 58 (and had bunch of other filters on proportions, color and carat). But the moment I increased table to 59, there were 13 diamonds. So it more than doubled the number of options.

This made me wonder what are the trade-offs associated with going to 59 table in this size range, assuming all other proportions were in the tight range (ie HCA < 2). Any inputs would be great.

When you go to a 59 to 60 table that would be considered a 60/60 diamond which means more white light return and less fire, lots of threads discussing this flavor of cut. Look at the depth on the stones at 59 to 60 table should be close to 60 hence 60/60 diamond. Nothing wrong with this flavor but the side profile view is not very appealing and looks like a flat top or “ pancake “. Most people on PS prefer a more balanced stone with a smaller table. The benefit of a 60/60 stone is that you get a more “ spready “ stone in mm size so more bang for your buck if that’s what you like.

 

[marrduk24]

When you go to a 59 to 60 table that would be considered a 60/60 diamond which means more white light return and less fire, lots of threads discussing this flavor of cut. Look at the depth on the stones at 59 to 60 table should be close to 60 hence 60/60 diamond. Nothing wrong with this flavor but the side profile view is not very appealing and looks like a flat top or “ pancake “. Most people on PS prefer a more balanced stone with a smaller table. The benefit of a 60/60 stone is that you get a more “ spready “ stone in mm size so more bang for your buck if that’s what you like.

Would something like this be classified as 60/60? Obviously it’s closer to 60/60 but not 60/60.

Let’s there was another diamond that had same crown angle, pavilion angle & depth but the table was 56. Is the science that it is likely to have more fire & scintillation vs the diamond with 59 counterpart? Obviously I understand that IRL it’s possible this particular 59 diamond may have more F/ S. But just trying to figure out what would one observe on an average if theoretically one could theoretically see 100s of diamonds that controlled for all other factors and only factor that varied was table.

 

[jp201845]

I don’t think this would be considered a 60/60 diamond because the depth is over 61 but the pavillion could be problematic at 41 with GIA rounding but if you really are interested in this stone I suggest posting advanced images Aset/Idealscope and also link a video the experts will chime in....

 

[marrduk24]

My question wasn’t as much on this stone. I used this stone only as an example.

My question is little bit more abstract/ conceptual. Let me frame it differently - let’s say you have two 3.5 carat diamonds of same color and clarity. Both have 34 crown, 40.8 pavilion, 61.5 depth. One has 56 table and one has 59 table. If one were to generalize the differences between two in terms of how they would appear to naked eye at close distance under different lighting conditions, how would one describe the differences?

 

[jp201845]

My question wasn’t as much on this stone. I used this stone only as an example.

My question is little bit more abstract/ conceptual. Let me frame it differently - let’s say you have two 3.5 carat diamonds of same color and clarity. Both have 34 crown, 40.8 pavilion, 61.5 depth. One has 56 table and one has 59 table. If one were to generalize the differences between two in terms of how they would appear to naked eye at close distance under different lighting conditions, how would one describe the differences?

One stone will be more balanced giving equal scintillation and fire and the other one will favor more white light return and less fire... hope that answers your question.

I should also note that the steeper the crown say 35 and smaller table 55 the more bold and intense fire you will get and vice versa the more shallow crown say 33 paired with a 59 table the more white light return you will get with short flashes of fire and less intense...

There are a lot of threads explaining this in more detail than what I’m trying to explain and also I’m not an expert just read a lot of threads.

 

[Garry H (Cut Nut)]

Close enough to 60:60 because with the table being a bit smaller the depth should increase.
But large tables on large diamonds will only work for pendants and earrings.
You are right to stay 58 or less.
But there should be firey ideal proportioned stone waiting for you.
And IMHO H is too low unless you have strong blue fluoro to improve the color. You will see the color in +2ct round diamonds. 1ct H in most fancy shapes is bad too.

 

[Garry H (Cut Nut)]

 

[marrduk24]

Thanks Garry. Hope you can answer one more question. For a ring out of 33/41.2 and 35/40.6 what would be a better combination. Both have HCA under two. Let’s say table was 57 and depth was 61.8%. I understand that 33/41.2 will be more bright and 36/4.6 would be more fiery. But I find it hard to relate to those concepts unless I feel one has seen 100s of diamonds to know how those differences in proportions translate to real life differences in the optical quality.

 

[oldminer]

When I search the Pricescope database for someone, I restrict my initial search for round diamonds to not larger than a 58% table and a crown angle of 34 to 35 degrees. I use GIA3X and look for Excellent HCA and not less than an "Average" Looks Like" score, too. With that combination, I can find the best of the GIA graded stones. Many times, there are very few stones to find. When that happens, I open the table to 59 and widen the crown angle from 33.5 to 35.5. I may open UV fluorescence from Faint up to Medium so long as the consumer has no objection to some fluorescence. That's about as far as it generally takes to find well cut diamonds to choose from.

There is more to searching for diamonds than the above, but this is a good start for how to find better and best cut stones within the GIA3X range.

Of course, that's not the entire process. When a super-ideal is desired, the search is narrower and there is a less wiggle room.

 

[marrduk24]

When I search the Pricescope database for someone, I restrict my initial search for round diamonds to not larger than a 58% table and a crown angle of 34 to 35 degrees. I use GIA3X and look for Excellent HCA and not less than an "Average" Looks Like" score, too. With that combination, I can find the best of the GIA graded stones. Many times, there are very few stones to find. When that happens, I open the table to 59 and widen the crown angle from 33.5 to 35.5. I may open UV fluorescence from Faint up to Medium so long as the consumer has no objection to some fluorescence. That's about as far as it generally takes to find well cut diamonds to choose from.

There is more to searching for diamonds than the above, but this is a good start for how to find better and best cut stones within the GIA3X range.

Of course, that's not the entire process. When a super-ideal is desired, the search is narrower and there is a less wiggle room.

How do you specifics exact crown and pavilion angle on PS? I have seen the option of specifying depth, table and HCA score rating but not CA & PA?

 

[oldminer]

Open up a Search and then select Show Filters.
You can specify table % and crown angle in the "Advanced" which is a choice to click on at the bottom right, above the diamonds listed in the initial search. This opens up a second page you can fill in to limit the search better.

You cannot specify pavilion angles. I think the HCA does a very good job eliminating the need for that data, so it is not problematic, in my opinion. That is automated by the HCA tool.

I believe many searches are made never realizing that a lot more can be specified. It really is helpful to show the filters and also make an advanced search.

 

[marrduk24]

Open up a Search and then select Show Filters.
You can specify table % and crown angle in the "Advanced" which is a choice to click on at the bottom right, above the diamonds listed in the initial search. This opens up a second page you can fill in to limit the search better.

You cannot specify pavilion angles. I think the HCA does a very good job eliminating the need for that data, so it is not problematic, in my opinion. That is automated by the HCA tool.

I believe many searches are made never realizing that a lot more can be specified. It really is helpful to show the filters and also make an advanced search.

Not to take it on a detour, but I have been using advanced search functionality for a while and I don't think there is a way to specify crown angle. It has depth, table, symmetry, polish, overall cut and fluorescence.

 

[oldminer]

You are totally correct. It is the depth, not crown angle. I manually eliminate too shallow or too steep. The HCA does a good job with the problem, too. Sorry for the mis-statement.

 

[Garry H (Cut Nut)]

Thanks Garry. Hope you can answer one more question. For a ring out of 33/41.2 and 35/40.6 what would be a better combination. Both have HCA under two. Let’s say table was 57 and depth was 61.8%. I understand that 33/41.2 will be more bright and 36/4.6 would be more fiery. But I find it hard to relate to those concepts unless I feel one has seen 100s of diamonds to know how those differences in proportions translate to real life differences in the optical quality.

Simply:
The shallower crown as pendant (might be a bit big for earrings?).
The steeper as a ring.
That is my clear perefernce.
The fire is what catches your eyes in a larger diamond!

 

[scarlettzzhang]

Simply:
The shallower crown as pendant (might be a bit big for earrings?).
The steeper as a ring.
That is my clear perefernce.
The fire is what catches your eyes in a larger diamond!

Hi Gary, thanks for the useful information. Does smaller table (say 55 vs. 57) would also produce more fire if the crown angle and pavilion angle are the same for the 2 diamonds?

 

[Garry H (Cut Nut)]

Hi Gary, thanks for the useful information. Does smaller table (say 55 vs. 57) would also produce more fire if the crown angle and pavilion angle are the same for the 2 diamonds?

Definitely.
The light entering and leaving the crown creates most of the fire you see from more or less straight on.
Very big table and low crown angle - a rough measure of fire in DiamCalc

and a nice stone

 

[shelly801]

Definitely.
The light entering and leaving the crown creates most of the fire you see from more or less straight on.
Very big table and low crown angle - a rough measure of fire in DiamCalc

and a nice stone

Hi Garry! All things being equal, including angles, would you go for a 57% table for a round brilliant over a 58%? Thank you!!

 

[Garry H (Cut Nut)]

Hi Garry! All things being equal, including angles, would you go for a 57% table for a round brilliant over a 58%? Thank you!!

definitely 57.5%!

 

[Garry H (Cut Nut)]

The answer really is not than simple.
Below a carat in most proportions sets 58-60%.
Above 5ct round as small as practical.
Lots and lots of variables!

 

[shelly801]

The answer really is not than simple.

Below a carat in most proportions sets 58-60%.
Above 5ct round as small as practical.
Lots and lots of variables!

totally makes sense! Thank you so much for the response! If you don’t mind, would you lean one way over the other between these two 2.75 carat diamonds? I realize the color and clarity are different but the vs2 didn’t have any visible inclusions without magnifications. There’s about a $1k difference in pricing. Or is it just whichever one looks better in person because the proportions are so close?

 

[Garry H (Cut Nut)]

It also needs to be understood that fire starts when light enters a diamond.
It is hard to show this in DiamCalc because the high angle of incidence makes a wide ray, but enlrged like this you can get clues

 

[Garry H (Cut Nut)]

This is better

 

[Garry H (Cut Nut)]

This should be in Lab grown diamonds, not natural section. I reject the first stone on HCA score.

 

[shelly801]

S

This should be in Lab grown diamonds, not natural section. I reject the first stone on HCA score.

Sorry! I didn’t realize. Is it best to have the stones in between 1-2? I think the first came in at .9.

 

[Garry H (Cut Nut)]

Sorry, my bad.
It would be hard to pick the difference.
But a VS2 if it has a VS1 or VVS inclusion as the plot indicates will probably be a little hazy from graning.
But you need to migrate to the grown diamond forum as I will not respond here any more and no one else should either

 

[Texas Leaguer]

All

As many of you know I was recently looking for a 3.5 to 4 carat diamond.

While researching one of the things I found was that a disproportionate number of diamonds in this size range had table > 58.

Eg when I recently looked at one of the sites, there were 5 diamonds when I capped table at 58 (and had bunch of other filters on proportions, color and carat). But the moment I increased table to 59, there were 13 diamonds. So it more than doubled the number of options.

This made me wonder what are the trade-offs associated with going to 59 table in this size range, assuming all other proportions were in the tight range (ie HCA < 2). Any inputs would be great.

@marrdduk24,
You may be bumping up against the fact that small deviations in proportions can have magnified impacts on the economics that a cutter must contend with in larger diamonds. If you look at the typical rough that rounds are cut from, the octahedron, there are often two diamonds that can be cost-effectively cut from it. One large and one small.



Cutting a larger table (shallower crown) can maximize the carat weight that can be derived from it, and on large stones where price/carat accelerates rapidly, the extra weight equates to significant $$ and makes the stone much more profitable for the cutter.

I think the issue of qualitative light return in diamonds with tables upwards of 60% has already been addressed in the thread. I will just make the comment that the built up crowns that diamonds with smaller tables usually feature also tends to enable them to capture light from more points in the lighting environment.

 

[Wink]

And IMHO H is too low unless you have strong blue fluoro to improve the color. You will see the color in +2ct round diamonds. 1ct H in most fancy shapes is bad too.

Gary, I strongly disagree with your assessment of color = bad. In my "blind taste tests" over the years, when I was showing people super ideal cut diamonds of various colors without saying anything about which color was which, I was amazed at how many people chose G-H-I colors as their favorite of the three to five diamonds on the slotted tray. Many people actually prefer the slight warmth of lower colors as opposed to the stark hard white of D-E-F.

I had been trained that color was bad when I got my GG, but seeing so many people love the lower colors forced me to realize I had been improperly trained. Once I got my own bias against color in diamonds put to the side, I was able to sell diamonds to those who wanted the best cut and sparkle with their diamonds, regardless of the color.

I have only had one client, @RunningwithScissors , come into my office who could tell the difference in colors instantly and actually identified the D from a distance of five or six feet as she walked towards my desk. I had five diamonds of 2 carats plus, including a D-E-F and two lower colors on the slotted tray. I was fascinated that she had detected it instantly from a distance and asked her to point them out in order. She did, correctly, while I had to refer to my cheat sheet to be sure I did not make any errors. She is an artist and has a highly trained eye for beauty, including color.

 

[Garry H (Cut Nut)]

There are often two diamonds that can be cost-effectively cut from it. One large and one small. Cutting a larger table (shallower crown) can maximize the carat weight that can be derived from it, and on large stones where price/carat accelerates rapidly, the extra weight equates to significant $$ and makes the stone much more profitable for the cutter.

No offence Bryan, but this is simplistic decades old wrong repeated often and still wrongly.
Firstly the planners do want to push the heaviest stones out of clean rough (where they do not need to avoid inclusions).
Second they do not leave any space as in your graphic.
Third the bottom stone in these examples tends to have a SMALL TABLE, steep crown and deepish pavilion and thick girdle, when there no other constraints (like cut grade systems). This is why so many diamonds fail HCA but are pushed to the upper boundaries of GIA X cut.
The top smaller stone by comparison tends to have a slightly deep pavilion, often very thin girdle and low crown height, which means larger table and to avoid a too large a table number, a shallow crown angle. These stones often record well on HCA and also nowadays on GIA as they appear to have seen the bright light (shining from these stones) and seem to have adjusted their lower X cut boundary.