Role of Leakage & Obstruction in Step-cut Facet Patterns?

[Karl_K]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

In my experience, looking only at table depth- even CA/PA overlooks a crucial aspect- corner size. The size of the triangles created by the corners is a vital element in an Emerald Cut's appearance in terms of glitter ( sparkle) liveliness- whatever we want to call it. I'd even say greater than table/depth.

Can I trouble Karl or anyone else to do a computer graphic predictor of large shoulders versus skinny shoulders for sparkliness?

This would be helpful -- pretty-please-with sugar-on-it, Karl or someone?

I know i did one for SE not sure for EC. I will see if I can find it if not will see what I can do.
It will be Monday however, I'm working all weekend and this afternoon.

 

[chrono]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

I so SO wish we have enough well cut EC options whereby we can select the right diamond based on corner size and other personal preferences. If just finding a well cut EC of any style, modern or classic, is already this difficult, adding more constraints will take forever to find the right EC and I doubt any lady is willing to wait that long for her engagement.

Lula,
My thanks for starting this thread and this might end up being a sticky or handy thread for those looking for the ultimate step cut. I started one such thread way back in early 2005 or 2006 when we knew even less about what makes a well cut EC. I agree that a shallow stone has a different look but it would be very helpful if this can be broken down into "hard" words the way Karl describes the pros and cons of classic versus modern.

Karl,
Thank you. I am more than willing to wait until Monday.

 

[Karl_K]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

I so SO wish we have enough well cut EC options whereby we can select the right diamond based on corner size and other personal preferences. If just finding a well cut EC of any style, modern or classic, is already this difficult, adding more constraints will take forever to find the right EC and I doubt any lady is willing to wait that long for her engagement.

Frankly I would talk to the dealers in the NY area who post on here and see if one of them was willing to go to a wholesaler or 2 and sort through what they have and find the best ones that meet your criteria.
Just don't expect rock bottom prices because it is expensive for them to take so much time away from the store.

Another option is to have a dealer who works with Yoram see what he has available. (Yoram cuts my Octavia but he also works with several of the PS vendors on other cuts.) This also would not be the cheapest option.

 

[Rockdiamond]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

snip.....

But shallow cut may come with its own set of problems, right?

snip.....

Bingo- what a great question!!

NO- there's nothing inherently "wrong" with a shallower diamond just like there's nothign inherently "right" about a small table high crown diamond. Shallow stones do seem to have a different "look" to them than deeper stones -- at least in my small sample -- especially when combined with large corners
This is why formulas do not work.Agreed -- I think it's much more helpful to talk of specific visual characteristics -- like corner size -- rather than numbers

Lula- love this thread.
It's honestly helped to broaden my perspective. Thanks -- that's nice of you to say, David
I'm totally spoiled when it comes to looking at stones, due to the manner in which I do it.
Clearly I've not taken enough time to look over the newly expanded listings with pics available to consumers online. The pictures and videos help; but they don't tell the whole story either, as they are 2-D and we see the stones in 3-D, under lighting conditions that may be very different from the lighting conditions in the vendor's showroom or photo lab.
Chrono- thanks in that regard too- I'm sure your experiences as a retail consumer are very much indicative of what others must be experiencing.

Re- the underlined part....
Lula, I don't doubt what your eyes told you when you were looking.....but just like we can't judge people based on what "group" they belong to......there's peril in using a small sample size to determine repeating patterns in emerald cut diamonds.

When I look through boxes of emerald cuts for purchase, I'm often surprised.
Stones with stats that seem to be quite appealing may be dogs when I open the paper- and conversely, stones that seem to have "wonky" numbers may be breathtaking in person.
Emerald cuts, in particular, play tricks on the eyes.
Shallow stones can take on a deeper (steppier) appearance due to facet placement on the crown, and pavilion.

 

[Lula]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

In my experience, looking only at table depth- even CA/PA overlooks a crucial aspect- corner size. The size of the triangles created by the corners is a vital element in an Emerald Cut's appearance in terms of glitter ( sparkle) liveliness- whatever we want to call it. I'd even say greater than table/depth.

Can I trouble Karl or anyone else to do a computer graphic predictor of large shoulders versus skinny shoulders for sparkliness?

This would be helpful -- pretty-please-with sugar-on-it, Karl or someone?

I know i did one for SE not sure for EC. I will see if I can find it if not will see what I can do.
It will be Monday however, I'm working all weekend and this afternoon.

Good things are worth waiting for! I'd be interested in seeing the results.
I think corner-size preference is something that might be worth discussing with consumers looking for advice on ECs.

 

[Lula]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

I so SO wish we have enough well cut EC options whereby we can select the right diamond based on corner size and other personal preferences. Agree 100%! If just finding a well cut EC of any style, modern or classic, is already this difficult, adding more constraints will take forever to find the right EC and I doubt any lady is willing to wait that long for her engagement. This is true; it seems that all purchases of fancies require some trade-offs. More than with RBs, because there are more "moving parts." Given my preference for square-ish ECs with wide corners, would I be happy with a longer, narrower EC with narrower corners, if the longer, narrower EC had more sparkle and flash? I don't know. But I think asking newbies looking for ECS to think about their preferences would be useful. I do know that posters are asked about preferences in terms of L x W ratio.

Lula,
My thanks for starting this thread and this might end up being a sticky or handy thread for those looking for the ultimate step cut.Thanks, Chrono. I think gathering up the many EC threads and photos in one place would be useful -- sort of like what Dreamer did with her old-cut thread. I started one such thread way back in early 2005 or 2006 when we knew even less about what makes a well cut EC. Is the 2005 thread you're referring to the thread that discusses ways to judge scintillation and dead spots in ECs by tilting the stone? I read several older EC threads that had some good visual assessment tips in them. I agree that a shallow stone has a different look but it would be very helpful if this can be broken down into "hard" words the way Karl describes the pros and cons of classic versus modern. Yes, I agree with this, because the shallowness of the cut is not the determining factor in either the performance or the visual appearance of the stone -- it's just one factor of many.

Karl,
Thank you. I am more than willing to wait until Monday. Ditto

 

[Lula]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

I so SO wish we have enough well cut EC options whereby we can select the right diamond based on corner size and other personal preferences. If just finding a well cut EC of any style, modern or classic, is already this difficult, adding more constraints will take forever to find the right EC and I doubt any lady is willing to wait that long for her engagement.

Frankly I would talk to the dealers in the NY area who post on here and see if one of them was willing to go to a wholesaler or 2 and sort through what they have and find the best ones that meet your criteria.
Just don't expect rock bottom prices because it is expensive for them to take so much time away from the store.Yes, this is the best way to get what you want -- after you determine your preferences. But, as Chrono mentioned, well-cut ECs are so hard to find, it's best to have flexible preferences!

Another option is to have a dealer who works with Yoram see what he has available. (Yoram cuts my Octavia but he also works with several of the PS vendors on other cuts.) This also would not be the cheapest option. But it might be quicker and a more sure way to find an EC that meets a consumer's visual preferences, e.g., large corners, more square shape. Maybe it's time for me to start a cottage industry in well-performing "classic" ECs

 

[Lula]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

snip.....

But shallow cut may come with its own set of problems, right?

snip.....

Bingo- what a great question!!

NO- there's nothing inherently "wrong" with a shallower diamond just like there's nothign inherently "right" about a small table high crown diamond. Shallow stones do seem to have a different "look" to them than deeper stones -- at least in my small sample -- especially when combined with large corners
This is why formulas do not work.Agreed -- I think it's much more helpful to talk of specific visual characteristics -- like corner size -- rather than numbers

Lula- love this thread.
It's honestly helped to broaden my perspective. Thanks -- that's nice of you to say, David
I'm totally spoiled when it comes to looking at stones, due to the manner in which I do it.
Clearly I've not taken enough time to look over the newly expanded listings with pics available to consumers online. The pictures and videos help; but they don't tell the whole story either, as they are 2-D and we see the stones in 3-D, under lighting conditions that may be very different from the lighting conditions in the vendor's showroom or photo lab.
Chrono- thanks in that regard too- I'm sure your experiences as a retail consumer are very much indicative of what others must be experiencing.

Re- the underlined part....
Lula, I don't doubt what your eyes told you when you were looking.....but just like we can't judge people based on what "group" they belong to......there's peril in using a small sample size to determine repeating patterns in emerald cut diamonds.Agreed.

When I look through boxes of emerald cuts for purchase, I'm often surprised.
Stones with stats that seem to be quite appealing may be dogs when I open the paper- and conversely, stones that seem to have "wonky" numbers may be breathtaking in person.
Emerald cuts, in particular, play tricks on the eyes.
Shallow stones can take on a deeper (steppier) appearance due to facet placement on the crown, and pavilion. Yes, I was surprised to see this effect in the EC I posted about in my other thread. It's a very shallow stone that has a better deep, hall of mirrors effect than the deeper stones I looked at. That's what made me curious about the role of contrast and leakage in patterning -- because there does seem to be a fair amount of skill on the part of the cutter to get a piece of shallow rough to look "deep."

 

[Rockdiamond]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

HI Lula,
I have not had a chance to see the other thread- and of course if it refers to another vendors stone, I can't comment on it anyway.

As you mentioned, photos, and even video tell a part of the story.
Add to this the fact that different vendors have different methods so it's also not possible to compare from one vendor to the next.

Physical reality of Emerald Cuts make this even more interesting:
Corner size is not mentioned anywhere on a GIA report.
Not that corner size alone is the determining factor- although it's important.
Facet placement is also not possible to ascertain by looking at a GIA report.

By all means, the most skilled cutters do it better than less skilled ones.
Do they think in terms of obstruction or leakage?
I seriously doubt it.

 

[Karl_K]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

My favorite is 28 but they are pretty much impossible to find. Many consider around 18 to be the sweet spot but many are cut at 10-12 for weight retention.

 

[woofmama]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

I've been following this thread with great interest. Thank you for all of the fantasic information.

Karlk on your diamond chart I prefer the diamonds between 18-21. If you recall I purchased the cut cornered step cut on JA that was shaped very much like diamonds 21 or up. I have found it difficult to find such dramatic clipped corners. Your chart will be very useful for finding shape preference when looking for ECs.

 

[chrono]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

I'll be delighted with anything from 18 through 28.

 

[Lula]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

Thank you, Karl! This is a very helpful chart. It's so much easier to describe the effect of corner size on the appearance of an EC with a visual than in words. I don't think I ever fully understood the relationship between corner size and sparkle in an EC until this thread and the tread on my JA stone.

My question is -- can larger corners mitigate a shallower crown? For example, given two ECs, both with crown heights of @ 9%, but one with corners the size of stone 18 in your diagram, and one with corners the size of stone 10 in your diagram, will the larger-corner stone have more life?

 

[Rockdiamond]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

Cool chart Karl!!
Of course in real life, we'd never see 28 stones with identical facet breaks, and different sized corners.

Lula- about corner size and crown height- there's too much potential variation in facet break placement to give a simple answer- these aspects work very closely together.
Change the facet break placement, and boom- you can get a very dark center- no matter table or corner size.

 

[Karl_K]

Re: Role of Leakage & Obstruction in Step-cut Facet Patterns

My question is -- can larger corners mitigate a shallower crown? For example, given two ECs, both with crown heights of @ 9%, but one with corners the size of stone 18 in your diagram, and one with corners the size of stone 10 in your diagram, will the larger-corner stone have more life?

In the corners and overall yes but the center area not so much.
Nothing can make up for it if the angles and facet location is not good.
There really is no one number that says this is a total dog or a really good one.
Everything has to work together to make a top of the line EC.