Cushion Cuts Under ASET Scope, is it me or the diamonds?!?

[Cushion4Life]

I have looked at a lot of cushion cuts utilizing the the ASET Scope kit purchased from ideal-scope. I purchased this exact kit: http://www.ideal-scope.com/cart_zoom_item.asp?Id=21&ShowAdd=Y

Sometimes when I put a cushion cut on the the little indent on the 'Ideal Light' and look at I see a lot of green and white when i look at it through the scope. When I say "a lot" I mean that the diamond looks almost all white with some parts green. Does this mean the diamond has a lot of leakage and a VERY poor cut or am I not using the ASET scope right?

I just have a hard time believing that out of the 5 cushion cuts this guy showed me 3 looked like the above.

Any thoughts or feedback?

Thank you!

 

[darren]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

Sounds like you are using the viewer correctly. The white does represent leakage and it is entirely possible for 3 out of 5 cushions to have a large amount of leakage and pull in a majority of indirect lighting through the crown.

 

[thbmok]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

I agree with darren. As far as I know AGS is the only major lab that issues cut grades on cushions, so unless your vendor is showing you AGS stones exclusively, I wouldn't be surprised that the majority are duds under the ASET.

 

[CharmyPoo]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

I am sorry but it sounds like you are looking with cushions with tons of leakage. My cushions have plenty of red under an aset scope.

Take a look at GOG's website - there are examples of cushion aset images there.

 

[TheGreatTwizz]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

I have looked at a lot of cushion cuts utilizing the the ASET Scope kit purchased from ideal-scope. I purchased this exact kit: http://www.ideal-scope.com/cart_zoom_item.asp?Id=21&ShowAdd=Y

Sometimes when I put a cushion cut on the the little indent on the 'Ideal Light' and look at I see a lot of green and white when i look at it through the scope. When I say "a lot" I mean that the diamond looks almost all white with some parts green. Does this mean the diamond has a lot of leakage and a VERY poor cut or am I not using the ASET scope right?

I just have a hard time believing that out of the 5 cushion cuts this guy showed me 3 looked like the above.

Any thoughts or feedback?

Thank you!

Don't have a hard time with that. Sadly, that is the reality of the cushion market. It seems like when a cutter has an otherwise clear, colorless stone, and no way to make the 'most' of it with a round, they make it a poorly cut cushion. You should ABSOLUTELY be seeing red and green. Yes, the white is leakage .

I just finished up my purchase of a 2.43 carat cushion, utilizing the same 'kit' from the same vendor. I looked at OVER 50 stones with that kit, and nearly ALL of them looked as you described. I thought it was me, too, until I would ask a vendor for an AGS 000 round, then saw the difference. Also, look at the CZ that came with your kit. You'll see the red/green/blue as it is supposed to be. If you search through my posts, you'll see some ASETs posted of that 2.43, and I can confirm to you that it is what the stone looked like in person, under the ASET.

It seems like you're looking for something similar to what I was, and I can tell you, it wasn't an easy search and took me over 2 months to get the right one, but that time is still paying dividends. Stick with GIA and, where applicable, AGS stones. Also, instead of going by carat weight, go by measurements. The 2.81 EGL stone you posted is VERY deep; unless it is a superstar under the ASET, and can be had in the 15k range, I wouldn't personally vote for it. My 2.43 measures 8.5mm x 7.5 mm.

If I may make some recommendations to help you along: first, decide if you want square or rectangular. They carry different looks, and you'll be looking for different things. The more rectangular, the harder it is to find a good ASET performer. This is probably why all of the GOG AVCs are square. Then, decide on your measurements (i.e. at least 7.7x7.7, etc.). Then shop based on measurements, not on carat weight. I was shopping between 2.1 and 2.8, and ended up right in the middle.

 

[Cushion4Life]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

Thank you guys.

TheGreatTwizz...it does sound like we are looking for similar stones...Do you mind if I ask you for the specs and price of your stone? I'd love to get an idea of if my budget and specs are reasonable.

Thank you for confirming that it is NOT me responsible for the very poor to really non-existent ASET results I am seeing. The 2.81 I posted does pretty well under the ASET, not amazing, but good. Definitely not $15k, I wish. He wants $27k for it.

What are the measurements I should be looking for? I guess as far as LxW and depth then? I don't want it to be too shallow, but with a wide table that it loses brightness/scintillation either...I guess I'm not sure what the kind of maximum ranges are for that.


Here's what I am looking for, just to give some of you an idea:

Cushion Cut

- 2.6 to 2.99 carats
- Color: D to G
- Clarity: VS1 to SI 1 (but of course has to be "eye clean")
- Very Good/Excellent Cut
- Brilliant cut with facets, NOT the "crushed ice" look
- Square stone with a L:W ratio between 1 to 1.06
- EGL, GIA, AGS cert ( I am open because I believe I have to be for specs + price I want to spend)

 

[CharmyPoo]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

Many say that you can't shop for cushions by numbers but I had the most success when ..

Table: 49% to 56%
Depth: 63% to 69%

I am less concerned with symmetry and polish for cushions. I would even go to a good rating if GIA.

They say that squares are L:W at 1.00 to 1.04 but in my experience .. I start noticing off square at 1.02.

Also, look for the following GIA plot patterns to start weeding out.

Number 1 is what is described as an antique cut. Number 2 is the most common not crushed ice modern cushion plot. For a modern cushion, I much prefer the plot in 3 and 4 but they are rare and difficult to come by these days.


NOTE: There are always exceptions but the above are the guidelines I apply.

 

[CharmyPoo]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

For illustrative purposes, here are 3 types of cushions all in authentic Harry Winston micropave halos. The first one is what would be described as "crushed ice" look. I did not include the plots for these above because frankly .. I don't usually consider them although others do believe there are non-crushed ice looking modified cushion brillants. It just hasn't been my experience.

 

[TheGreatTwizz]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

Charmy is providing some good info here, and in my experience, the depth is necessary to get good light performance. I've seen some shallower cushions and they were just 'dead'.

My stone's specs and ASET are here:

[URL='https://www.pricescope.com/community/threads/cushion-eval-sarin-and-aset-included.167984/']https://www.pricescope.com/community/threads/cushion-eval-sarin-and-aset-included.167984/[/URL]

Finished product is here:

[URL='https://www.pricescope.com/community/threads/my-fiances-cushion-halo-from-barsky-diamonds-in-philly.169642/']https://www.pricescope.com/community/threads/my-fiances-cushion-halo-from-barsky-diamonds-in-philly.169642/[/URL]

That said, you'd think the large table (69.5%) it would lose something, but I don't find that it does at all. This thing is an absolute fireball in person, and frankly embarrassing in jewelry stores. I haven't previously disclosed what I paid for that stone, but I will say that it was significantly less than your budget and I was offered a profit on it when I had it evaluated.

I think you might be missing some great stones by setting your bottom limits at 2.6. Again, when I searched, it was 2.1-2.8. I found nothing out there that was 2.8-2.99 anyway (they'd have cut it to be over 3 otherwise), and most (not all) of the stuff that was under 2.1 was cut to get it over the 2ct mark and didn't perform well. Again, not a 'rule', just what I found in my experience. I would think that you should get at least a 7.7mm+ stone.

Unless looking at AGS, IGNORE the cut rating. Let me repeat myself: IGNORE THE CUT RATING if not AGS. It is worthless, period. Keep in mind that the color is what you're paying a premium for, and an EGL G could be a GIA I. It's a good deal on the face because you're getting a G stone cheaper, but when its not really a G stone........

I'm not going to get into the whole EGL debate here, but if you've read thoroughly, you'll find that the majority of this forum will only recognize AGS and GIA certs due to their consistency. Is not that EGL ALWAYS grades softer, they just aren't CONSISTENT about their grading. It is virtually guaranteed that without a master stone reference kit, you will not be able to tell the difference between a G stone and an I stone. Color is one of the biggest premiums on a stone. Be a bit flexible there, and your world will open up.

Lastly, have you looked at A Cut Beyond Cushions from ERD? They of course carry a premium for being branded, but here is an H/SI1 that appears eye clean, and is in budget. Mark is a terribly nice guy, and while I never bought from him, many here have and I can see why he is held in high regard. I also had great luck with James Allen.

http://www.engagementringsdirect.com/2.46-carat-h-si1-a-cut-beyond-cushion-cut-diamond-gid-64670.html

 

[Rockdiamond]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

Hi All,
A few things to keep in mind:
1) Using experience garnered after looking at a limited number of stones does not produce workable rules. IOW, if someone has seen shallower stones that had no sparkle, or livliness, it's not a safe assumption that depth is necessarily to have a lively cushion. there are indeed lovely cushions with lower depths- that may also have the advantage of a larger face up.

2) I agree that any cut grade on a cushion not issued by AGSL is to be ignored.
However even AGSL cut grade itself does not enjoy broad support from experts.
Some like it , some feel it's excluding some very well cut stones.

3) for an uninitiated consumer, ASET is incredibly difficult to interpret- and even use properly.
If a consumer has ASET photos provided by a vendor, then PS members can, at least, assist a consumer in interpreting the ASET.
Then we have the interpretation- again by no means agreed upon
Is Green better than Red in an aset?
Not all experts agree on this.
Is crushed ice bad?
This entire subject is subjective.

Cushion4Life - basically- I think your difficulty using the aset is very understandable, and not uncommon- it's not easy to use.
Second, you'll get very specific opinions here- and that may be great.
For people who have studied what they love- aiming for a given plot, or depth or table will produce the results they desire. THis can be VERY helpful, if you love the same things as those giving these opinions.
But not everyone will.

 

[Cushion4Life]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

CharmyPoo - Thank you for the GIA plot patterns and the different pictures of actual rings. That is really helpful. So out of the 5 GIA plot patterns you listed, selecting one I like is really just a matter of taste and how I think they look? Are there plot patterns outside of the ones listed that I should ignore? GIA is the only place where the facet patterns are relevant, correct?

TheGreatTwizz - I read both the (your) threads you linked to all the way through. Some very good discussion and your ring looks gorgeous from all the pictures. A couple things regarding my color predisposition to G or above is that I want the stone to "look white". However both yours and the ERD link you sent me appears white. That is an H and yours is a J, so maybe I am being too anal retentive about the G or above color.(?) I hear you on the EGL G color could really be an GIA I or J. Many of the EGL stones I looked at definitely appeared almost yellow, certainly not G. I go into looking at EGL stones knowing they will be off on color and clarity, but to what degree I dont know. I will say that if I found a stone I loved and it was an EGL, I would absolutely have it independently appraised before completing the purchase.

Rockdiamond - I have tried not to solely rely on the ASET. I will say that when I look through it and the stone is secured on the "made for it" groove on the light board and I put can place the ASET scope flat around it and look in and see nothing but literally white and a few green specks...I instantly get turned off.

 

[CharmyPoo]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

Cushions are very much personal preference based but for folks that have seen plenty of cushions in real life often have a lean towards what they find beautiful.

Tables: Smaller tables with higher crowns gives the diamond a refined looked. I do not like larger tables on cushions because it gives the effect (for lack of a better description) of a helicopter landing pad. It is just large and flat .. not so appealing to me.

Shallow Cushions: There are some companies that make a living advertising and selling shallow cushions (Daussi cushions is an example). RD is correct that cushions can be lovely with lower depths - but in my mind only to some people. No different than saying that eye visible black carbon inclusions can be lovely - it is true .. some people like it. I have seen sufficient examples of cushions with extreme low depths for me to conclude that they lack fire and scintillation. In fact, I own a beautifully facetted cushion that is very shallow - it has a lovely pattern but lack fire because of its shallowness. It does benefit from look very large though.

Plots: I simply don't like Modified Cushion Brilliants and I avoid all associated plot patterns. This is me though and there are many others who are ok with it. I just don't like how they look but that is my opinion. They don't have the edge to edge patterns.

In the end, diamond light performance is simply science - it's a matter of how light enters and exits based on the internal properties of the diamond and how it is cut. There is no disputing that. The judgment comes from personal preference and beauty is in the eye of the beholder.

 

[slg47]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

Cushions are very much personal preference based but for folks that have seen plenty of cushions in real life often have a lean towards what they find beautiful.

Tables: Smaller tables with higher crowns gives the diamond a refined looked. I do not like larger tables on cushions because it gives the effect (for lack of a better description) of a helicopter landing pad. It is just large and flat .. not so appealing to me.

Shallow Cushions: There are some companies that make a living advertising and selling shallow cushions (Daussi cushions is an example). RD is correct that cushions can be lovely with lower depths - but in my mind only to some people. No different than saying that eye visible black carbon inclusions can be lovely - it is true .. some people like it. I have seen sufficient examples of cushions with extreme low depths for me to conclude that they lack fire and scintillation. In fact, I own a beautifully facetted cushion that is very shallow - it has a lovely pattern but lack fire because of its shallowness. It does benefit from look very large though.

Plots: I simply don't like Modified Cushion Brilliants and I avoid all associated plot patterns. This is me though and there are many others who are ok with it. I just don't like how they look but that is my opinion. They don't have the edge to edge patterns.

In the end, diamond light performance is simply science - it's a matter of how light enters and exits based on the internal properties of the diamond and how it is cut. There is no disputing that. The judgment comes from personal preference and beauty is in the eye of the beholder.

excellent post!!!

 

[yssie]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

In the end, diamond light performance is simply science - it's a matter of how light enters and exits based on the internal properties of the diamond and how it is cut. There is no disputing that. The judgment comes from personal preference and beauty is in the eye of the beholder.

Is it redundant to thritto?

 

[Rockdiamond]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

There's no question that light enters a diamond, some bounces back, some goes away from the eye- all very scientific.
The aset is a means of determining where the diamond is gathering light from - nothing more, nothing less.
It's the interpretation of the results that are completely subjective- and not at all scientific.
For example, is green bad? Is red more desirable?
If we want to test, in a scientific, methodical manner, don't we need to consider other light sources such as diffuse light sources, multiple light sources?
What about light gathered by the pavilion the diamond?
Once we include the word "performance" it ALL becomes subjective.


In terms of table size- working with Fancy Colored diamonds sometimes allows a more..."open minded" perspective on cut.
Basically I look at stones cut very differently than "traditional" cut- and can do so with a more open mind.

A small table does have certain aspects that affect the overall appearance- and that many people find desirable.
A larger table ( within reason) does exactly the same thing.
Personally I don't find a comparing a large table/small table with a black spot/ clean diamond to be illustrative.
I think we can agree that if we showed a diamond with no black spot compared to one with a visible black spot, the percentage of folks picking the spotted one will be tiny.
Not so if we're comparing well cut examples of "Chunky" with "Crushed Ice" ( as I define it) - or small tables with large.
Many people will pick the shallower stone- or the stone with the larger table.
Many people shy away from the patterns associated with smaller table/higher crown
The reason is that there are attributes that come with a shallower crown, larger table design, for example.
One of them is a very even, crushed ice appearance. The antithesis of a "chunky" or patterned style of cut. In good examples, it IS edge to edge brilliance.
Many would call this better light performance than a patterned stone more suited to the type of ASET analyzation commonly done on PS.

 

[denverappraiser]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

A stone that shows a lot of green is collecting light from <45 degrees and reflecting it back at 90 degrees. A stone showing red is reflecting light from >45 degrees back to the 90 position. The assumption that red is better than green is because most lighting environments have lights in the ceiling and that’s above 45 degrees when looking down the C-axis of the stone (that’s the direction perpendicular to the girdle plane). There is generally more light coming from high angles so a stone that's good at collecting and returning this will be brighter than stones that collect from low angles. Cutters have become very skilled at maximizing this and the result is a round brilliant cut stone of proportions that are well known around here. Look at the stone from directly above with good lights right behind your head and you get a fireball. I suspect you already knew that and if that’s what you wanted you wouldn’t be buying a cushion in the first place. The trick comes when the light source and/or the stone moves and when the viewing angle is something OTHER than 90 degrees. In an ASET, light that reflects back to, say 75 degrees, is lost and presumed failure but is it really? Why? What if that’s the viewing angle in ‘real life’? You may not be able to interfere with passing air traffic as well as your H&A friends but in low angle lighting, like candles, a properly cut cushion can be AWESOME.

Patterning is a big deal on cushions but, other than hearts and arrows fans, is almost completely ignored by people shopping round brilliants. It’s 100% a taste issue. The expected pattern for rounds is well known and assumed but cushions can look very different from one another. It’s not just ‘performance’ issues. Terms like ‘crushed ice’ and ‘chunky’ make no sense with a round but they’re the first thing you notice in a cushion.

Unfortunately, I see quality of cutting on fancy’s getting worse even as it improves for rounds. A cutter is going to take a particular piece of rough and target it for a path to the most money. That's their job. One choice is super-ideal rounds. One choice is barely-ideal rounds. One is VG but heavy rounds. They all have their merits. some go for something else, like cushions, princesses, pears etc. Rounds are something like 85% of the market share. They're popular, they sell fast and they sell for a premium. Those are pretty good reasons. With the others, the issue is generally how to get the maximum weight. You've surely noticed, that's a premium too. Rather few are cut for optics and, unlike rounds, they don’t get saddled with a cut grade that says it’s crap. This decision is made strategically and very carefully and it’s ALWAYS about the money. There are a few cutters cutting fancys to maximize optics (and who charge a premium to do it), and there are some old ones that just got lucky, but the new cutters are using computers to get exactly what they want in terms of results and what they generallly want is WEIGHT.

 

[Rockdiamond]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

A stone that shows a lot of green is collecting light from <45 degrees and reflecting it back at 90 degrees. A stone showing red is reflecting light from >45 degrees back to the 90 position. The assumption that red is better than green is because most lighting environments have lights in the ceiling and that’s above 45 degrees when looking down the C-axis of the stone (that’s the direction perpendicular to the girdle plane). There is generally more light coming from high angles so a stone that's good at collecting and returning this will be brighter than stones that collect from low angles. Cutters have become very skilled at maximizing this and the result is a round brilliant cut stone of proportions that are well known around here. Look at the stone from directly above with good lights right behind your head and you get a fireball. I suspect you already knew that and if that’s what you wanted you wouldn’t be buying a cushion in the first place. The trick comes when the light source and/or the stone moves and when the viewing angle is something OTHER than 90 degrees. In an ASET, light that reflects back to, say 75 degrees, is lost and presumed failure but is it really? Why? What if that’s the viewing angle in ‘real life’? In low angle lighting, like candles, a properly cut cushion can be AWESOME.

Patterning is a big deal on cushions but, other than hearts and arrows fans, is almost completely ignored by people shopping round brilliants. It’s 100% a taste issue. The expected pattern for rounds is well known and assumed but cushions can look very different from one another. It’s not just ‘performance’ issues. Terms like ‘crushed ice’ and ‘chunky’ make no sense with a round but they’re the first thing you notice in a cushion.

Unfortunately, I see quality of cutting on fancy’s getting worse even as it improves for rounds. A cutter is going to take a particular piece of rough and target it for a path to the most money. That's their job. One choice is super-ideal rounds. One choice is barely-ideal rounds. One is VG but heavy rounds. They all have their merits. some go for something else, like cushions, princesses, pears etc. Rounds are something like 85% of the market share. They're popular, they sell fast and they sell for a premium. Those are pretty good reasons. With the others, the issue is generally how to get the maximum weight. You've surely noticed, that's a premium too. Rather few are cut for optics and, unlike rounds, they don’t get saddled with a cut grade that says it’s crap. This decision is made strategically and very carefully and it’s ALWAYS about the money. There are a few cutters cutting fancys to maximize optics (and who charge a premium to do it), and there are some old ones that just got lucky, but the new cutters are using computers to get exactly what they want in terms of results and what they generallly want is WEIGHT.

We agree on the part in blue- I would go farther and include all kinds of every day lighting environments other than candle light where a cushion ( or radiant) might use the light gathered from lower angles in a more attractive way to a lot of viewers as compared to a stone gathering light from more overhead sources.

The part in red is simply a prejudicial statement Neil.
A very large presumption grouping cutters together like that- what applies to some does not apply to all.
There's some very talented cutters out there- in fact, today's savage business environment has culled the field considerably. I agree that there's a lot of junk on the market, but there's also a WIDE variety of EXCELLENT cutters of Fancy Shaped Diamonds operating today.
Of these excellent cutters- what is the prime motivation?
Same as ANY other business. To stay in business, and to stay profitable.
Are some totally money hungry people looking only to cut the heaviest possible diamond- sure.
But generalizations are going to unfairly group people together unfairly.
Chalk up my indignation about this type of generalization to the fact that I have close personal friends who are cutters of fancy shapes.
The best ones place beauty high on the list of priorities, they get higher prices, and possibly sell more easily.
What really irks me is that such generalizations make everyone look stupid- buyer and sellers alike.
Sure there are dealers that are looking to maximize profits with no consideration to fine makes- or even fair business practices.
But what about buyers ( at the wholesale level) smart enough to see value in fine makes. NOt all that common, but they certainly exist.
Therefore a market for a wide variety of well cut fancy shapes does exist.
Contrary to Neil's experience, I've seen some very large cutting houses get exponentially better at cutting fancy shapes over the past 10 years.

I realize that if we include mass marketers, the numbers are skewed far towards the bleak picture Neil painted- but this forum is generally not about that type of seller- most readers of PS aren't shopping at typical mall jewelers for fancy shaped diamonds.

Then we have the term "optics".....this is a hot button for me.
If we're suggesting that some don't cut for optics, why would a cutter cut for "optics" as suggested by Neil?
To make money? Again, they're also running a business.
So what are the people cutting for weight doing- cutting with their eyes closed? Trying to make ugly diamonds?
What about the motivation of those we may identify ( using these assumptions) as "cutting for optics".
Do they also need to consider yield?

If a cutter decides that a given piece of rough should be cut into a shape that may maximize yield, do they completely ignore how the diamond is going to look? (it's optics)

I've heard a statement made ( here) that old diamonds were not cut for optics.
Did cutters of yore consider how the diamond was going to look ( it's optics)? OF COURSE.
Are the optics of a round "better ( scientifically) than those of a given cushion?
To make definitive "scientific" statements like that, we'd need to tackle the part about where a diamond gathers light from- and which is "better" scientifically.
Therefore "Optics" is not a word that works in these discussions without a lot of explanation.

 

[dreamer_dachsie]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

OP you are looking in person so you have the ability to use tool and plots and then calibrate them to what your eyes see. I tkink you will easily form your own preferences by using your eyes if you look at enough stones with a wide range of plots and also a range of ASET appearances. The tools are good because I think they can help you be certain you are really seeing a wide range of cuts. My concern in general with telling people to *only* use their eyes to look and judge a diamond is that they ususally are presented with a circumscribed range of appearances -- generally, a whole bunch of poorly cut stones Using the plots and ASET to help you be sure you are seeing examples of different types of cuts makes it more certain you can form an impression of what you really like knowing you have "seen it all" so to speak. Then you can use the tools to hone in on the cut style you want and desire. Good for you! I like to see a consumer educating themselves about an expensive purchase.

 

[Rockdiamond]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

Wow a real presidential candidate here on PS!!!
Joking aside, welcome to PS RonPaul

Ron- if the brain remembers dark parts of cushions, does it not do so with other shapes? Like the arrows on a H&A stone?

Is it possible that the larger table of stones you're dismissing as "cheaper flat top diamonds" gathers a lot of light from areas around the head and lower angles that are part of what makes crushed ice so attractive?

I agree that a frame of context is vital- and looking at many different type of cushions, including branded stones is a great help to consumers.
But if we tell them what's "better" ( based on someone's personal preference) first - would it be possible that will influence the experiment?

 

[Rockdiamond]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

I guess then the question might be, what sort of light return does one prefer.
I agree that dark areas in the diamond that are persistent do not look good to most onlookers, including me.
We can use the example of what I would call a "detrimental bowtie" that you might see in a Pear or Marquis..
It's not that the best cut Pear or Marquis has no bowtie whatsoever ( although some don't), but the dark areas flash to light very quickly.

The same phenomenon occurs in cushion shaped diamonds – maybe that's what you mean. stones with large static dark areas are not attractive. There are very beautiful crushed ice type diamonds that have dark areas that are constantly flash on off bright– like the hearts and arrows type of thing. Just not organized into a pattern like that.

I also agree that looking at 50 diamonds is not an education.
Of course, for the average consumer, 50 is probably way more than they will probably examine first hand. They can get a pretty good idea by examining a dozen diamonds
But if one was to look only at diamonds cut to maximize light return measured in the way you suggest- and not a wide variety of Cushion Brilliant, Cushion Modified, Old Mine Brilliant- then the education is no more complete.

I agree- consumers are better served when exposed to more choices, along with a good explanation of what they are seeing..

 

[Rockdiamond]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

I agree that, if trying to find a cushion diamond off a list is non productive.
I agree that a fair percentage on the list are stones many people, including me, will agree are really badly cut.
Some may have flat top, some may be too deep. Some have unattractive pavilion design, large facets in all the wrong places, dull lifeless appearance- yes that all exists- and a great goal of this forum is to educate consumers.

There are certainly stones cut with specific optical goals- and in some cases these stones may command a premium. I feel that it is certainly worth that premium for buyers who prefer the same optical properties.
It takes more rough to cut these stones, the research that goes into the design- this all means something- and is worth something.

However if one makes assumptions about "crushed ice" diamonds- they are doing education a disservice as well.
There are indeed extremely well cut, gorgeous crushed ice colorless diamonds. There has been a lot of research, and experimentation on how to produce lovely crushed ice stones.
These diamonds do not exhibit the patterns a H&A type of stone will and also show a lot of red, green and some areas of white on an ASET- yet they can be amazing to look at in person. This suggests to me that analysing them is less effective using ASET as opposed to looking at them. That is to say- the ASET will help you find one type of stone ( patterned)- but not necessarily the other.
Some of the biggest, and most respected names in the business specialize in gorgeous, well cut, non patterned, pinfire cushions ( AKA crushed ice).
That does not make them right.
But it certainly lends credibility to my defense of them

 

[Cushion4Life]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

This thread has been a great source of information and it seems there has been some good lively discussion. I've read every word!

While I know others have already weighed in above talking about table vs depth...Is there a good range of positive table percentages for a brilliant cushion, facet plot 1 in CharmyPoo's above post? or other plots for that matter? Everyone is talking about the different facet plots, but if it is NOT he modified brilliant, aka "crushed ice", is there a real difference in light performance and look? What face plot is equivalent to the Cushy Brilliant Chunky, as shown in CharmyPoo's pictures?

What about culet? I am not sure how a cut with an open culet (of varying) sizes will look once mounted in a ring. I will tell you that I DO NOT like the idea of being able to hold a loose diamond up and be able to see black, brown, etc through the center. I just don't know enough about what effect the culet will have once mounted. So I guess I would be interested in the culet vs non-culet camps.

Lastly, how important is symmetry in a GIA stone? Particularly a, Good vs Very Good?

 

[CharmyPoo]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

First - read this: [URL='https://www.pricescope.com/community/threads/cushion-cut-help-request-w-pictures.170097/#post-3095529#p3095529']https://www.pricescope.com/community/threads/cushion-cut-help-request-w-pictures.170097/#post-3095529#p3095529[/URL]

Back to the basics - I compiled pictures of various square cuts in the past. The photos are mostly from GOG.


Here are examples of plots versus real diamond examples. I pulled this together years ago so it is pretty outdated and there are better examples now.




Now to answer your questions. I know you want other opinions so hopefully people will chime in.

Q: While I know others have already weighed in above talking about table vs depth...Is there a good range of positive table percentages for a brilliant cushion, facet plot 1 in CharmyPoo's above post? or other plots for that matter?
I believe the ideal table and depth percentages for all cushions plots is as follows.
Depth: 63% to 69%
Table: 49% to 56% (but you can go higher)
These are very general and you really have to see how it works with the pavillion and crown angles.

Q: Everyone is talking about the different facet plots, but if it is NOT he modified brilliant, aka "crushed ice", is there a real difference in light performance and look?
As illustrated above and in your other thread, there is a huge difference in look depending on the facet plot. All plots will have diamonds that are well cut and poorly cut. Short of it - there is a real difference between facet plots but also with each diamond you are looking at. In my opinion, the only cushions truly cut for "light performance" are the August Vintage Cushion, square H&A and BGD's modern cushion. Although I must admit that I am not a fan of the BGD cushion.

Q: What face plot is equivalent to the Cushy Brilliant Chunky, as shown in CharmyPoo's pictures?
Plot #1

Q: What about culet? I am not sure how a cut with an open culet (of varying) sizes will look once mounted in a ring. I will tell you that I DO NOT like the idea of being able to hold a loose diamond up and be able to see black, brown, etc through the center. I just don't know enough about what effect the culet will have once mounted. So I guess I would be interested in the culet vs non-culet camps.
Most modern cushions will not have a culet. Plot 1 very often has a culet and it can be any size. As a loose diamond, you will see a hole but it isn't black or brown - it is whatever is in the background. Once set, most culets are not noticable in real life (photos yes). I hated culets but I don't mind them now.

Q: Lastly, how important is symmetry in a GIA stone? Particularly a, Good vs Very Good?
Obviously, excellent would be best and the higher the rating the better. However, I am comfortable with going to Good. My modern cushion has a GOOD symmetry rating if I recall correctly. I don't think it takes away from the diamond but obviouslt the higher the better. I wouldn't let this be the show stopper as finding the other stats is hard enough.

 

[CharmyPoo]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

It seems there were a bunch of posts that I have in my email notification but don't see here. I am including the snippets that are important for your reference as you search for your cushion.

I suggest going out and seeing branded cushions or at least cushions where an extra consideration was made to returning high angle light to the viewer. Go see a SCHA, AVC, Quadex, Brellia, Princess Of Hearts. Even seeing some vintage facetedstones like ERD's A Cut Beyond.

Your eyes should be able to spot the brightness differences between these and the average large table Cushion. Correlate this with ASET images and you will have a good frame of reference.

I also think that a balanced discussion on this topic should also include the opinion that there are very bright cushions out there those that are not HA and are much more efficient at returning light than large table cushions. I beleive this is the point Charmypooo was trying to make.

Correct - one of the points I am trying to make.

I don't anyone should be telling them which one is better overall in a subjective sense. There are pros and cons of both, the big pro in favour of the modified cushion brilliant with the flat crown is its price/carat.

Pretty easy to find the flat top CMBs don't you think? I'd say 90%+ of the cushions available on virtual lists are these. Consumers don't need pricescope to find one of these.

 

[Cushion4Life]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

CharmyPoo (and everyone else contributing) - Thank you for all your information. It's amazing. I just posted a specific diamond for you on the other thread.

 

[Cushion4Life]

Re: Cushion Cuts Under ASET Scope, is it me or the diamonds?

Thought you guys would be interested in final product:

https://www.pricescope.com/community/threads/cushion-cut-2-4cwt-mark-erd-engagement-ring.172818/