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How do vendors grade cut quality of fancy shapes?

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affguy

Shiny_Rock
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I've got my search for an emerald cut diamond narrowed down to two stones, one an F IF, 63% table, 66.5% depth and the other a D VVS1 with 65% table and 65.2% depth. Both are GIA VG polish/symmetry, but the IF's cut is listed as excellent whereas the VVS1's is listed as VG. Are these likely to be subjective evaluations by a gemologist? Or a standard practice of giving one grade higher than pol/sym? Or are there actually some standards by which these grades are given?
 
Others with more experience on the nuances of fancy cut grading can give you more information about the differences in EX, VG, and G in fancies. But in my own experience searching for an emerald-cut, both online and in local stores, there seems to be very little correlation between visual beauty and the numbers/cut grade. The numbers and grade do seem to have some correlation to price, e.g., a stone that is cut deeper may receive a lower cut grade, and should be sold at a lower price due to the extra depth.
 
affguy|1326817043|3105133 said:
I've got my search for an emerald cut diamond narrowed down to two stones, one an F IF, 63% table, 66.5% depth and the other a D VVS1 with 65% table and 65.2% depth. Both are GIA VG polish/symmetry, but the IF's cut is listed as excellent whereas the VVS1's is listed as VG. Are these likely to be subjective evaluations by a gemologist? Or a standard practice of giving one grade higher than pol/sym? Or are there actually some standards by which these grades are given?

Completely- and IMO it's very misleading to see cut grades listed on sites as if they have some meaning. There is no established cut grade for Emerald cut Diamonds.
AGSL does have some cut grading on Fancy Shapes- but even that is by no means agreed upon by the trade.

Have you been able to see these stones in person? Or at leasyt good photos and videos?

To make it even more complex, the polish and symmetry rating are virtually unconnected to how the stone will look ( as long as they're a minimum of "Good")
In other words, a fancy shaped G/G stones can be 100% better cut than another stone that got EX/EX
 
Rockdiamond|1326821652|3105183 said:
affguy|1326817043|3105133 said:
Have you been able to see these stones in person? Or at leasyt good photos and videos?

Unfortunately no. The only significant jewelers within a couple hundred miles of me are of the mall store variety (Kay, Ben Bridge, etc). My budget is quite slim for this stone (for my own wedding ring), and spending travel money to go shopping would trim the budget even further, so I'm going with a pricescope vendor and just trying to shop by numbers and cross my fingers. On the plus side, if I make a mistake, at least it won't be an expensive one, and if the stone is flat out ugly, I do have a 30 day return window. These two stones are priced almost identically, so I'm just wondering if the cut grade actually means anything or can be ignored entirely.
 
To answer your orignal question: Dart board? 8)
 
The aspects that appeal to me are things like corner size, and he way the steps gather and return light.
There are vendors with photos. They may not be the least expensive- but on this type of a purchase I always advise consumers t look at photos.
The money back guarantee may be sufficient for you though- but even looking at the site with photos may be informative to you- see if you can see differences that matter
 
Rockdiamond|1326823323|3105204 said:
The aspects that appeal to me are things like corner size, and he way the steps gather and return light.
There are vendors with photos. They may not be the least expensive- but on this type of a purchase I always advise consumers t look at photos.
The money back guarantee may be sufficient for you though- but even looking at the site with photos may be informative to you- see if you can see differences that matter

David, this is very helpful information. Can you please elaborate a bit more about what consumers should look for in photos? Dark areas? Irregular patterning? I'm not sure if the mods would allow this, but it sure would be useful to see some examples of photos that show how the steps are gathering and reflecting light.
 
David is correct, the GIA does not issue cut grades on fancy stones. The AGS does have some fancy shapes that it issues cut grades on based on light performance criteria which is determined by ray tracing the gems.

Thus any cut grade offered on an emerald cut with a GIA report is the dealer's own grade and has, actually, no value to an educated buyer. In fact it should set off alarm bells to an educated buyer that the vendor is willing to make claims that can not be backed up to entice you to buy or not buy sight unseen. Then when your eyes do not agree you do not have any real recourse since the stone meets the criteria that was set by the vendor. (Translation, always insist on a view and return period, the longer the better.)

While much can be inferred from a good ASET photo as to how a gem will look in real life, with fancy shapes there IS NO SUBSTITUTE FOR SEEING THE GEM!. Actually this is good advice for any gem, but especially for fancy shaped gems, as what you may love another may find vanilla, or worse.

I do not sell many fancy shapes, but in reality, how I grade them is how I see them. If I am looking at a fancy shape gem that is a little sparkle here and a little sparkle there, I pass. If I am looking at a fancy shape gem that has edge to edge sparkle, then I am looking at something I might be interested in. Of course with an emerald cut you are looking for a completely different look and a more "stated elegance" than mad crazy sparkle.

I have seen two emerald cuts in my life that I wanted to own, and thus owned both of them only for a very short time. I have seen many that were very very nice and worthy of being sold and of course I have seen bucket loads of them that were relatively lifeless lumps of crystallized carbon that I would not even consider owning or selling. All of those determinations were made instantly with the eye, and that is how I recommend that you grade the diamonds that you are looking at.

Wink
 
Rockdiamond|1326821652|3105183 said:
affguy|1326817043|3105133 said:
I've got my search for an emerald cut diamond narrowed down to two stones, one an F IF, 63% table, 66.5% depth and the other a D VVS1 with 65% table and 65.2% depth. Both are GIA VG polish/symmetry, but the IF's cut is listed as excellent whereas the VVS1's is listed as VG. Are these likely to be subjective evaluations by a gemologist? Or a standard practice of giving one grade higher than pol/sym? Or are there actually some standards by which these grades are given?

Completely- and IMO it's very misleading to see cut grades listed on sites as if they have some meaning. There is no established cut grade for Emerald cut Diamonds.
AGSL does have some cut grading on Fancy Shapes- but even that is by no means agreed upon by the trade.

Have you been able to see these stones in person? Or at leasyt good photos and videos?

To make it even more complex, the polish and symmetry rating are virtually unconnected to how the stone will look ( as long as they're a minimum of "Good")
In other words, a fancy shaped G/G stones can be 100% better cut than another stone that got EX/EX

LOL, I was actually referring to this comment in this post in my post above, but there were several intervening posts since the phone rang and I was occupied for the last hour or so.

Wink
 
Howdy Wink :wavey:

I'll admit it it- I am a total sucker for emerald cuts.
It's like, if you imagine a cartoon diamond, it's an emerald cut- so it's like a diamond shape from my dreams as a kid.

Lula- that is a great question!
I will look for a few photos that I can post to give you an idea.
IN terms of dark areas, multiple photos, and especially video are very good at showing if dark areas are static, or if they flash bright with a little movement.
But in general, a great looking emerald cut will always have some dark facets.
In the best cases they are adjacent to a bright facet- and even more so adjacent facets that flash light and dark quickly ( equaling glitter)
 
Thanks, Wink and David.

David, I guess where I am confused is on the balance between light and dark facets. I know I've seen some emerald-cuts that show almost a maltese cross pattern of dark facets. And I've also seen some emerald cuts that look like flat white squares, with almost no hall-of-mirrors effect. A good emerald cut should have a 3-D like appearance, correct? The steps drawing you into the stone. So the flat, white emerald-cuts seem to lack that 3-D effect. I'm not sure what's going on with the very dark stones -- obstruction? I'm going to post some random photos that I've collected from ebay (none are PS rings that I know of).

The first one I'm curious about is this 3-stone. What's going on here? Is this obstruction? Tilt angle? I see lots of emerald cuts that look like this -- both online and in local jewelry stores.
Thanks for your feedback :wavey:

ec02.jpg
 
HI Lula,
I love this discussion!
One thing I've never gotten the hang of the concept of assigning a cause, like obstruction for dark areas in a stone- or why it matters. When we examine the diamond, we need surely see the effects, from a physical standpoint
If a stone has a dark area, and it's static ( does not change), and it's unpleasant, I really don't care why.
The photo does indeed look like a good example of what to avoid, in my opinion. The dark area in the center of the stone does not seem to have a lot of gradiants of darkess- which may be a clue that the dark area does

I will say that photographing Emerald Cut three stone rings is a nightmare.
The perfect angle to set the side stones from a construction standpoint generally puts the side stones at a horrible angle to the camera.

Here's two photos of a stone I photographed back in 2008. I really liked the cut of this stone
In the first photo, the dark areas are fairly pervasive- yet theres' still sharply defined gradients of darker areas.
r2564f.jpg

However tilted a bit, and moved to a different background we can see a nice display of "steppiness"
r2564a.jpg

For this reason multiple photos are really a plus
 
Rockdiamond|1326845796|3105454 said:
HI Lula,
I love this discussion!
One thing I've never gotten the hang of the concept of assigning a cause, like obstruction for dark areas in a stone- or why it matters. When we examine the diamond, we need surely see the effects, from a physical standpoint Okay, I see your point here.
If a stone has a dark area, and it's static ( does not change), and it's unpleasant, I really don't care why. This comment is very useful to me as a consumer. I never thought of the dark areas as static or not. Or the dark areas as pleasant or not. So, if I'm understanding you correctly, a dark area that does not move and change as as the stone is one indication of a less-than-desirable EC?
The photo does indeed look like a good example of what to avoid, in my opinion. The dark area in the center of the stone does not seem to have a lot of gradiants of darkess- which may be a clue that the dark area does [/b] This makes sense. Again, it's hard for me to tell what's bad photography and what's poor cutting. [/b]

I will say that photographing Emerald Cut three stone rings is a nightmare.
The perfect angle to set the side stones from a construction standpoint generally puts the side stones at a horrible angle to the camera. Yeah, I can see where three-stone step cuts would pose a huge problem for a photographer. Good to know, though, when looking at a variety of shots of the same ring from different angles, how each of the three stones may react differently to the light source

Here's two photos of a stone I photographed back in 2008. I really liked the cut of this stone
In the first photo, the dark areas are fairly pervasive- yet theres' still sharply defined gradients of darker areas.
r2564f.jpg Yes, this photo helps me see that some darkness in a step cut is necessary to give the stone its 3-D, or hall of mirrors effect.

However tilted a bit, and moved to a different background we can see a nice display of "steppiness"
r2564a.jpg

For this reason multiple photos are really a plus

Thank you so much, David. This discussion has taught me a lot. I still have a long way to go in evaluating light-dark areas in photographs of step cuts. But I'm starting to be able to recognize the differences between stones that appear to be overall too dark, and stones that are showing a pleasing light-dark pattern. I'm also learning that there is no correlation between grading report numbers and real-life appearance. Dang. And I am such a numbers girl ;))
 
Great discussion Lula!

One aspect I've always had a hard time with, here on PS, is the way a diamond's cut is somehow evaluated.

Take the subject of Obstruction.
Scientifically, it's interesting.
But it does not get me from here to there in figuring out what a good cut is for me.


So rather than look at the numbers like crown height, instead I focus on what my eye sees.
I mentioned static dark areas. Darkness in diamonds is an essential element of contrast, which results in the sparkle. To me, areas that stay dark in a stone are a less attractive element.

Speaking of numbers, the stone I posted was 59.5% depth, 58% table size, G/G

I don't have the stone anymore to measure, but generally the smaller table is indicative of a fairly high crown- which I believe this stone had. I've heard it said here many times that crown height is essential for a great looking EC- however my own practical experience has not neccesarily shown that to be the case.
Sometimes a shallower stone with the right corners and pavilion can make a spread ( large) emerald cut with great life.
 
Rockdiamond|1326927519|3106215 said:
Great discussion Lula!

One aspect I've always had a hard time with, here on PS, is the way a diamond's cut is somehow evaluated.

Take the subject of Obstruction.
Scientifically, it's interesting.
But it does not get me from here to there in figuring out what a good cut is for me.


So rather than look at the numbers like crown height, instead I focus on what my eye sees.
I mentioned static dark areas. Darkness in diamonds is an essential element of contrast, which results in the sparkle. To me, areas that stay dark in a stone are a less attractive element.

Speaking of numbers, the stone I posted was 59.5% depth, 58% table size, G/G

I don't have the stone anymore to measure, but generally the smaller table is indicative of a fairly high crown- which I believe this stone had. I've heard it said here many times that crown height is essential for a great looking EC- however my own practical experience has not neccesarily shown that to be the case. But I just threw out two from my short list that had very small tables, one with 14 or 16% crown height, that were duds according to the vendor. So I am even more curious about the relationship of crown height, crown angle, and table size to the stone's appearance. Will a taller crown produce more fire?
Sometimes a shallower stone with the right corners and pavilion can make a spread ( large) emerald cut with great life. But if the stone is too shallow, I've heard that it looks "watery" which I interpret to mean not displaying a clear hall of mirrors effect.

Is it the bottom of the stone that is the most critical -- the p3 angles? With the crown height, table size, and crown angle reflecting personal preference?

ETA: I'm not sure if I'm making any sense. Maybe a better way to say this is, is it the p3 angles on the bottom of the stone that determine how well the stone handles light, and how bright and lively the stone appears as it is moved? And is crown height, table size, and crown angle less important to the way the diamond handles light, and more a matter of personal preference. For example, someone who wants to see more colored flash may prefer a higher crown? Someone who prefers a brighter, spreadier stone may prefer a larger table?
 
Lula- when the vendor called them "duds", did they give you any sense of the visual weaknesses they saw?
Did you see the stones in pictures?

Regarding questions about the p3 angles, crown height, ca and table size: I have the luxury of getting to evaluate stones that are right in front of me.
Plus, since I look at a lot of fancy colors, I get to see many non traditional combos in my daily routine.
I have found that each stone is unique- for reasons like the fact that every piece of rough offers different possibilities in the cutting of fancy shapes.
Sometimes this means a stone that clearly is cut to hold weight in the belly- but in other cases it involves using a shallow piece of rough to produce a great looking "spready" stone.
It's almost rare to find a "textbook" example. Since I like large corners, my "textbook" example may be different than yours.

What this experience has taught me is to remove the statistics from my consideration when I'm making a first judgement. Sometimes a stone that has numbers which seem promising does not please my eye- and other times stones with weird numbers prove to be magnetic to my eye.

Since we're on a board where internet sales are prevalent, most people want to find some sort of workable formula. For a stone like an emerald cut, where exceptions to the rule are sometimes the most exceptional stones, working inside numerical boundaries makes no sense, if you can look at the stones.
In a case of a consumer like you- someone who really has a fine and discriminating eye, you're just going to have to start with photos- and get a good money back for any stone you buy.
Buy a ticket to your dealer and go see stones in person.
Bottom line is that you will be able to effectively narrow your search using photos, video, and measurements. But you will only be able to make your final decision in person.
 
Lula, I've seen a lot of step cuts because they interest me and because my own engagement ring is an asscher. If I were buying a step cut again I would do the same thing we did with this one. Call a trusted vendor with guidelines -- color, clarity, l/w ratio, and depth (70) and table (66) maximums. And I, personally would want a crown height over 14%. Then, I would tell them vendor that I wanted the brightest best performing stones they could find. Once the vendor had narrowed it down to 3 stones then I would go and see them in person and play with them as much as possible in all different light. I really think in person is best for step cuts. They can have a lot of quirks. If the vendor would agree to send the stones (at my cost for shipping) to a local appraiser, I would go there and chose. And if they wouldn't then... I would ask the vendor for as many pics (and yes a video too) as possible, and then ask them which they would chose. Then I would have the top two sent to me (fully paid for on credit card) and then I'd return the stone I didn't like.
 
Thanks, RD. I appreciate your insight.

The vendor did not use the word "dud"'; that's my terminology. But the vendor did say that in person both stones were dark and that they couldn't recommend either of them to me. Which I very much appreciate. They provided images and Sarin reports and cautioned me that even in the case of the stone with @14 % crown height, that the stone would likely not be bright enough for me. So I feel the images and numbers only provide part of the story. We agree on that.

So far my in vivo inspections have been constrained by what's available in my local jewelers. Which is not much of a selection. The used market is actually better than the "new" market. I have spent a lot of time "training" my eye over the past few years. It's difficult. I am only now starting to be able to "see" differences among a group of emerald cuts, i.e., some flash clear prism-like bars of colors with just a little movement. Some don't show much color at all, but show white-grey-black "stripes" when moved, but aren't lively the way the stones that show colored flash are. And some show a very dark cross in the center that seems to be present under all lighting conditions and at all angles. It's hard to make meaningful comparisons with just a few stones. It's also hard to make meaningful comparisons when I am not clear what is is I'm supposed to be looking for when I move the stone around. If I had to make a personal choice, I'd say I'd choose a stone that displayed the most colorful prisms when tilted. I'd also take a good look at the girdle to check for chips and thin spots. That's the sum total of my knowledge thusfar :lol:

I do think a plane ticket would be a wise investment. If only just to see some decent emerald-cuts in real life. I just don't think the stock available to me here in a small Midwestern city is going to yield anything but stones cut for weight not beauty.
 
Gypsy|1326932298|3106277 said:
Lula, I've seen a lot of step cuts because they interest me and because my own engagement ring is an asscher. If I were buying a step cut again I would do the same thing we did with this one. Call a trusted vendor with guidelines -- color, clarity, l/w ratio, and depth (70) and table (66) maximums. And I, personally would want a crown height over 14%. Then, I would tell them vendor that I wanted the brightest best performing stones they could find. Once the vendor had narrowed it down to 3 stones then I would go and see them in person and play with them as much as possible in all different light. I really think in person is best for step cuts. They can have a lot of quirks. If the vendor would agree to send the stones (at my cost for shipping) to a local appraiser, I would go there and chose. And if they wouldn't then... I would ask the vendor for as many pics (and yes a video too) as possible, and then ask them which they would chose. Then I would have the top two sent to me (fully paid for on credit card) and then I'd return the stone I didn't like.

Hmm, I like this appraiser idea a lot. This could work. Thank you. I'm just curious about your decision to go with a crown height over 14%. What do you see in step cuts with taller crowns? More fire? More life? I have to admit, I just have no clue what I'm looking at when I examine step cuts. I feel like I'm starting from 0. Bah. Rounds are so much easier.
 
HI Lula,
Here's why I don't feel the appraiser idea is so hot.
First of all, how well an appraiser loves a stone is not necessarily relevant to how any individual might love the diamond.
Second- whatever resources are allotted to paying the appraiser could be used to put you in a better position to view more stones personally- by traveling to either NY or LA where there's a greater concentration of stones.


In terms of crown height- I see it as a red herring.
Some stones with a greater crown height look great to me- but so do some stones with shallower crown height.
So if you make crown height a deciding factor you will eliminate some very nice candidates.
 
Rockdiamond|1327000374|3106788 said:
HI Lula,
Here's why I don't feel the appraiser idea is so hot.
First of all, how well an appraiser loves a stone is not necessarily relevant to how any individual might love the diamond.
Second- whatever resources are allotted to paying the appraiser could be used to put you in a better position to view more stones personally- by traveling to either NY or LA where there's a greater concentration of stones.


In terms of crown height- I see it as a red herring.
Some stones with a greater crown height look great to me- but so do some stones with shallower crown height.
So if you make crown height a deciding factor you will eliminate some very nice candidates.

David, I agree with you in the case of "new" emerald-cut stones. In that case, a visit to vendor(s) in NY or LA would certainly pay off. In the case of a vintage or ebay emerald cut, where the vendor is god-knows-who, I think using an appraiser -- especially one who is willing to make a video of the stone -- is a safe option that is well worth any fee.

ETA: But, even in the case of a purchase of a new EC from a vendor in NY or LA, I'd still have the stone evaluated by an independent appraiser, just for verification's sake. I'm still not one to take a jeweler's statements about their goods at face value, no matter how charming that jeweler may be. Read too many horror stories on here to not take that extra step!
 
Lula,if a seller is questionable, they're not going to send the stone to a third party. I suppose that's good reason to send a stone to an appraiser. If the seller is a crook, this will scare them away.
But an honest private individual would most likely be very hesitant to send a stone to a third party they do not know..

If the discussion is about how well established vendors will feel about sending stones to an appraiser- they're likely going to be more amenable to it- but again, I question the value.
If you are concerned that a seller either does not have the ability to make sure they're sending the stone referred to on a GIA report- or you're concerned they'll intentionally send the wrong stone, an appraiser makes good sense.
What does not make sense to me is why to buy from such a seller in the first place.

You mentioned "horror stories" you've read here on PS- did any of those involved vendors that are generally recommended here?
 
Rockdiamond|1327005170|3106838 said:
Lula,if a seller is questionable, they're not going to send the stone to a third party. I suppose that's good reason to send a stone to an appraiser. If the seller is a crook, this will scare them away.
But an honest private individual would most likely be very hesitant to send a stone to a third party they do not know..

If the discussion is about how well established vendors will feel about sending stones to an appraiser- they're likely going to be more amenable to it- but again, I question the value.
If you are concerned that a seller either does not have the ability to make sure they're sending the stone referred to on a GIA report- or you're concerned they'll intentionally send the wrong stone, an appraiser makes good sense.
What does not make sense to me is why to buy from such a seller in the first place.

You mentioned "horror stories" you've read here on PS- did any of those involved vendors that are generally recommended here?

No, fortunately not. The horror stories typically involve ebay purchases or NY diamond district purchases (which you, and other vendors, have warned posters about). I've worked with Wink for several years, and never bothered to have anything I've purchased from him sent to an independent appraiser. Likewise, I probably wouldn't have a stone sent to an independent appraiser that was purchased from the vendors most commonly recommended here.

But very often on ebay you'll see stones for sale by private sellers (broken engagements, etc.) and in these cases, I would make the sale contingent on inspection by an independent appraiser. Often the seller has no paperwork, no clue about the cut, color, clarity of the stone -- it's a real risk buying from sellers like that. Though I do agree with you, most sellers would probably balk at sending the stone to a third party. The appraisal transaction would have to be arranged by me after the stone was sent to me, in cases like that.

Also, let's say I made the trip to NY or LA and found a diamond at a jewelry store (non PS vendor) in one of those cities. In that case, I would again ask that the sale be contingent upon an inspection by an independent appraiser. So I think I'm being confusing when I'm using the words "sending it to an independent appraiser." I'm thinking more in terms of buyer purchases stone from seller, seller offers return period, buyer takes the stone to the appraiser, buyer keeps or returns the stone, depending on how buyer feels about the results of the appraisal.

I do think in the case of fancy cuts, I know so little, that I'd really want another pair of eyes to look at the diamond. Take a look at my thread on the small EC I was considering -- there was so much good input about cut, clarity, carat weight -- important considerations. My eyes are not trained on what to look for in an EC. So I am easily swayed by the "oh, it's so pretty" aspect of shopping for an EC. At this stage of my search, most EC's look alike. I'm a prime candidate for an unscrupulous seller!
 
Lula|1326925079|3106182 said:
Rockdiamond|1326845796|3105454 said:
HI Lula,
I love this discussion!
One thing I've never gotten the hang of the concept of assigning a cause, like obstruction for dark areas in a stone- or why it matters. When we examine the diamond, we need surely see the effects, from a physical standpoint Okay, I see your point here.
If a stone has a dark area, and it's static ( does not change), and it's unpleasant, I really don't care why. This comment is very useful to me as a consumer. I never thought of the dark areas as static or not. Or the dark areas as pleasant or not. So, if I'm understanding you correctly, a dark area that does not move and change as as the stone is one indication of a less-than-desirable EC?
The photo does indeed look like a good example of what to avoid, in my opinion. The dark area in the center of the stone does not seem to have a lot of gradiants of darkess- which may be a clue that the dark area does [/b] This makes sense. Again, it's hard for me to tell what's bad photography and what's poor cutting. [/b]

I will say that photographing Emerald Cut three stone rings is a nightmare.
The perfect angle to set the side stones from a construction standpoint generally puts the side stones at a horrible angle to the camera. Yeah, I can see where three-stone step cuts would pose a huge problem for a photographer. Good to know, though, when looking at a variety of shots of the same ring from different angles, how each of the three stones may react differently to the light source

Here's two photos of a stone I photographed back in 2008. I really liked the cut of this stone
In the first photo, the dark areas are fairly pervasive- yet theres' still sharply defined gradients of darker areas.
r2564f.jpg Yes, this photo helps me see that some darkness in a step cut is necessary to give the stone its 3-D, or hall of mirrors effect.

However tilted a bit, and moved to a different background we can see a nice display of "steppiness"
r2564a.jpg

For this reason multiple photos are really a plus

Thank you so much, David. This discussion has taught me a lot. I still have a long way to go in evaluating light-dark areas in photographs of step cuts. But I'm starting to be able to recognize the differences between stones that appear to be overall too dark, and stones that are showing a pleasing light-dark pattern. I'm also learning that there is no correlation between grading report numbers and real-life appearance. Dang. And I am such a numbers girl ;))

I would like to take a WAG at these three pictures.

In the first picture, not shown in this post, the stones are obviously cut very poorly as the dark areas are at wildly different angles and thus more than just a result of obstruction. Whether too deep or too shallow is not important, they are just to yucky to matter.

In the second set of photos, it is looking to me as if the first picture is suffering from obstruction, largely caused by the lens of the camera being too close to allow light to reach the diamond. This is rectified in the second photo at a slightly different angle. We can see, even with the obstruction, that different angles are obstructed differently and that this diamond has the potential, as shown in the second photo, to "shine" when the light is allowed to hit the facets involved.

It is just as easy to see why he might not like it in the first picture as it is to understand why he likes it in the second. (Of the pictures in this post.)

It is also an outstanding example of why you MUST see a stone that you think you might like, as what if that obstructed view totally turns you off to the diamond, no matter how great it looks with only a few degrees of change in the tilt of the gem? The second gem that he is showing is definitely worth a look if you are looking for that type of gem and it is likely that you would like that gem when you saw it, but you can never know until it is seen, with your eyes.

Nice illustration of a vexing problem for photographers David. How do we keep a good stone from looking bad, and just as importantly, how do we keep a bad stone from looking good?

Wink
 
Lula said:
snip...
So I am easily swayed by the "oh, it's so pretty" aspect of shopping for an EC. At this stage of my search, most EC's look alike. I'm a prime candidate for an unscrupulous seller!

I think you're selling yourself WAAAAAY short Lula.
You could probably teach salespeople in your local jewelry stores about diamonds, and jewelry - and I believe you could teach them a lot.

For example- I don't even know you personally- but I could not imagine you walking into an unknown store on 47th street and buying anything.
Ok, maybe a pack of gum :)
 
LOL! I think you know her much better than you think you do. Lula could indeed give lessons to most "jewelers" let alone their sales reps!

Wink
 
Wink|1327006896|3106869 said:
Lula|1326925079|3106182 said:
Rockdiamond|1326845796|3105454 said:
HI Lula,
I love this discussion!
One thing I've never gotten the hang of the concept of assigning a cause, like obstruction for dark areas in a stone- or why it matters. When we examine the diamond, we need surely see the effects, from a physical standpoint Okay, I see your point here.
If a stone has a dark area, and it's static ( does not change), and it's unpleasant, I really don't care why. This comment is very useful to me as a consumer. I never thought of the dark areas as static or not. Or the dark areas as pleasant or not. So, if I'm understanding you correctly, a dark area that does not move and change as as the stone is one indication of a less-than-desirable EC?
The photo does indeed look like a good example of what to avoid, in my opinion. The dark area in the center of the stone does not seem to have a lot of gradiants of darkess- which may be a clue that the dark area does [/b] This makes sense. Again, it's hard for me to tell what's bad photography and what's poor cutting. [/b]

I will say that photographing Emerald Cut three stone rings is a nightmare.
The perfect angle to set the side stones from a construction standpoint generally puts the side stones at a horrible angle to the camera. Yeah, I can see where three-stone step cuts would pose a huge problem for a photographer. Good to know, though, when looking at a variety of shots of the same ring from different angles, how each of the three stones may react differently to the light source

Here's two photos of a stone I photographed back in 2008. I really liked the cut of this stone
In the first photo, the dark areas are fairly pervasive- yet theres' still sharply defined gradients of darker areas.
r2564f.jpg Yes, this photo helps me see that some darkness in a step cut is necessary to give the stone its 3-D, or hall of mirrors effect.

However tilted a bit, and moved to a different background we can see a nice display of "steppiness"
r2564a.jpg

For this reason multiple photos are really a plus

Thank you so much, David. This discussion has taught me a lot. I still have a long way to go in evaluating light-dark areas in photographs of step cuts. But I'm starting to be able to recognize the differences between stones that appear to be overall too dark, and stones that are showing a pleasing light-dark pattern. I'm also learning that there is no correlation between grading report numbers and real-life appearance. Dang. And I am such a numbers girl ;))

I would like to take a WAG at these three pictures.

In the first picture, not shown in this post, the stones are obviously cut very poorly as the dark areas are at wildly different angles and thus more than just a result of obstruction. Whether too deep or too shallow is not important, they are just to yucky to matter.

In the second set of photos, it is looking to me as if the first picture is suffering from obstruction, largely caused by the lens of the camera being too close to allow light to reach the diamond. This is rectified in the second photo at a slightly different angle. We can see, even with the obstruction, that different angles are obstructed differently and that this diamond has the potential, as shown in the second photo, to "shine" when the light is allowed to hit the facets involved.

It is just as easy to see why he might not like it in the first picture as it is to understand why he likes it in the second. (Of the pictures in this post.)

It is also an outstanding example of why you MUST see a stone that you think you might like, as what if that obstructed view totally turns you off to the diamond, no matter how great it looks with only a few degrees of change in the tilt of the gem? The second gem that he is showing is definitely worth a look if you are looking for that type of gem and it is likely that you would like that gem when you saw it, but you can never know until it is seen, with your eyes.

Nice illustration of a vexing problem for photographers David. How do we keep a good stone from looking bad, and just as importantly, how do we keep a bad stone from looking good?

Wink

Great question Wink!
My techniques are result based.
That is to say, I've never been able to put my finger on exactly what makes me feel a photo is representative- but I know it when I see it.
Many sellers use a specific setup, for every stone.
This adds consistency.
What it lacks is allowances for different types of stones, and different manner that they use light.
The same setup that give a great representation of a gorgeous "super ideal" Infinity stone might be horrible for a modified brilliant- or an emerald cut. They use the light so differently, that different setups are needed to take good representative photos.
Then within the cut of "emerald cut" there's different variations of PA/CA/Table/depth the each require different lighting considerations.

IMO, the goal of such photos should be accurate representation.
If the photo looks better than the stone, you'll get a lot of returns.
If it does not compliment the stone, it will turn off buyers.

Not an easy thing, photographing diamonds.....
 
Wink|1327006896|3106869 said:
I would like to take a WAG at these three pictures.

In the first picture, not shown in this post, the stones are obviously cut very poorly as the dark areas are at wildly different angles and thus more than just a result of obstruction. Whether too deep or too shallow is not important, they are just to yucky to matter.

In the second set of photos, it is looking to me as if the first picture is suffering from obstruction, largely caused by the lens of the camera being too close to allow light to reach the diamond. This is rectified in the second photo at a slightly different angle. We can see, even with the obstruction, that different angles are obstructed differently and that this diamond has the potential, as shown in the second photo, to "shine" when the light is allowed to hit the facets involved.

It is just as easy to see why he might not like it in the first picture as it is to understand why he likes it in the second. (Of the pictures in this post.)

It is also an outstanding example of why you MUST see a stone that you think you might like, as what if that obstructed view totally turns you off to the diamond, no matter how great it looks with only a few degrees of change in the tilt of the gem? The second gem that he is showing is definitely worth a look if you are looking for that type of gem and it is likely that you would like that gem when you saw it, but you can never know until it is seen, with your eyes.

Nice illustration of a vexing problem for photographers David. How do we keep a good stone from looking bad, and just as importantly, how do we keep a bad stone from looking good?

Wink
Thanks, Wink and David, for your compliments [blush] though, David, I'm not sure I'd trust even the gum being sold in the NY diamond district!

Thanks, Wink, for your comments about the photos. The portions of your response that I underlined really go to the heart of what I'm asking. As a consumer who has limited access to EC's in person, and who shops second-hand and estate and pawn shops, your comments are very helpful in assessing a stone's appeal, especially in the absence of lab reports. And you are so right -- there are EC's I've seen that look appealing from one angle, but are complete turn-offs from other angles. And in those cases, my reaction is almost visceral -- even if the price is right, I won't buy the stone.

David, yes, I very much agree with you that in the case of fancies, the numbers on the lab report provide few clues about the diamond's appearance in real life. That said, I do believe that there are a few separate and distinct "types" of ECs. In my own limited experience, I've seen*:

1. ECs that have an "open" look, with more subtle light-dark gradations. These stones appear whiter and brighter and the bars have a more random on-off, dark-light appearance.

2. ECs that have a dark, deep look with sort of a mono-chromatic step pattern (similar to the first picture) that is present when viewing the stone face-up. The dark pattern may or may not shift when the stone is tilted. Some of these ECS show the dark pattern on only two sides (similar to the first picture) and some show this dark pattern on all four sides (the dark "Maltese cross" pattern). Camilla's ring (Duchess of Cornwall) has this look in photographs. In this type of EC, the steps look blocky, not gradated.

3. ECs that have distinct rectangular-shaped dark and light patterns. These ECs have a distinct geometric light-dark pattern when viewed face-up, often with the centermost "rectangles" remaining dark face-up, and becoming lighter when the stone is tilted or moved.

* Forgot to add: I typically view ECs away from spotlights, and ask to look at the stones near a window and/or under fluorescent lighting. I find that spotlighting provides a misleading view of the stone, even more with fancies than with RBs.

I'll try to find photos, but ebay sellers have gotten smarter about using software that prevents copying of photos off the listings. I'll have to link the listings, I guess.

ETA: Just found a photo of a "Lula EC Type 3":

EC - rectangular bars.jpg
 
Nothing productive to add, just to say that this is a great thread and I'm following closely - thank you Lula, David, and Wink!

Lula I can't wait to see what you wind up with :sun: And I'll be really interested to read what you think of it after owning so many Infinity RBs - I can't think of more disparate styles!


Lula, of those types which do you like best, do you think? When looking at ECs (I've only looked at a few though) I tend to favour the ones with lots of alternating bands of light and dark - more, smaller steps. I guess because that's as close to an RB as they can get in terms of both appearance and light return! I don't think I like Lula Type 3s - I get impatient waiting for those giant facet-blocks to re-orient sufficiently to *do something* - especially in larger stones...
 
Well cut EC's should really be divided into 2 categories both beautiful in their own way but in my experience people have a strong preference between them.

The first is what some consider to be the classic shape:
Large table and fairly low crown.
Well cut they are bright and contrasty in diffused lighting and have large fire in other lighting but very few little small flashes.
They have almost entirely large scintillation events.

Then you have the smaller tabled and high crown ones.
They are also bright but not as contrasty with more med and small virtual facets(the are still very contrasty compared to a RB)
The have a lot more flashes with more small and medium scintillation events and to many look livelier.

Well cut both should dance when tilted, this is what static images can not show and why video is nice.

Imho you can not tell an EC is the ONE until you see it in person for a couple days in your own environment but using photos and video you can separate out one that has a high potential of being the ONE.
Actually I feel the same about any diamond cut.
 
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