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A Princess Too Good To Be True?

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researcher

Ideal_Rock
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I have found several diamonds in my search that are, according to everything I've read in this forum, excellent diamonds. However, the one I can't seem to stop my heart from beating fast over is an EGL graded diamond (and one that has to be accurate for me to really consider it b/c of color and clarity). What are your thoughts?

AGA Grade: 1A
Color: H
Carat: 3.44
Clarity: SI2
Crown: 9%
Pavilion: 56%
Depth: 66.7
Table: 70 (for this to be 5% less than the depth it would need to be 63.37)
Girdle: TN
Polish & Symmetry: Very Good
Dimensions: 8.68x8.56x5.71
Ratio: 1.01
 

viscera912

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Hello!

I am a fellow princess searcher as well. Please do not think of me as an expert in this field, however, I've been reading and learning here for a good amount of time. I've learned that one must be careful when considering an EGL stone. With that being said, apparently there are some EGL labs that are not bad, however, there are some known for their leniency on their grading. Thus, your H color diamond might be I or J. As far as your depth and table are concerned, they look dead on!!! Also, crown height is always a plus! I suppose the biggest thing here is if you totally like it. If it speaks to you then go and buy it! From the specs alone, it looks like a beautiful stone. It would be nice to snag an Idealscope test on it to see light leakage. Hopefully its eyeclean and the price is right, if it is then go for it!!!

Jason
 

researcher

Ideal_Rock
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Thanks for responding, Jason! I started out with a ridiculous amount of stones I was considering before doing my research, but now I've got a great list. There's one that is very sparkly on the optical reports--GIA 2B 2.36 E VS2--but I can't help but be drawn to the cut and size of the 3.44. I have also found 5-6 stones that are GIA 1A-1B 2.21-2.52 F-G VS1-2, but...what can I say? I am keeping my fingers crossed that the EGL was correct! I can't wait until my bf and I decide on our top 3 and have them sent to an appraiser so we can inspect them!

What size range are you looking for? I'd be more than happy to pass along any I find :) Isn't it funny how you can become so knowledgeable here? I have gone to several local diamond super stores (I live in San Diego) and have had the senior people there taking notes when I talk about how to judge the cut of diamonds (they hadn't even heard of the AGA grading charts and were unaware of trick to find a table 5% smaller than the depth)
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All I can say is I'm very thankful for sites like this!!!
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Good luck with your search!
Summer
 

Rhino

Ideal_Rock
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On 4/30/2004 9:24:44 PM researcher wrote:





I have found several diamonds in my search that are, according to everything I've read in this forum, excellent diamonds. However, the one I can't seem to stop my heart from beating fast over is an EGL graded diamond (and one that has to be accurate for me to really consider it b/c of color and clarity). What are your thoughts?

AGA Grade: 1A
Color: H
Clarity: SI2
Crown: 9%
Pavilion: 56%
Depth: 66.7
Table: 70 (for this to be 5% less than the depth it would need to be 63.37)
Girdle: TN
Polish & Symmetry: Very Good
Dimensions: 8.68x8.56x5.71
Ratio: 1.01
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A 9% crown... table is greater than depth ... what is it about this diamond that is getting you excited? These measurements sound like a recipe for disaster. Yes it will have a nice spread for a princess cut but it sounds like a leaker. Do you know crown/pavilion angles?
 

researcher

Ideal_Rock
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From my understanding a crown of 9-12% fits into the ideal for a princess cut. What I like about this stone is, for it's size, the specs match my criteria better than many of the others. Maybe I am wrong on how much of an impact things like ratio, symmetry, and girdle can have on a stone's performance, but I like the idea of having a 1A grade in cut, a girdle that doesn't vary (TN), a near 1:1 ratio (1.01), and very good symmetry/polish. Also, I read somewhere that as long as the pavilion % is close to the 55-60 range the angles should be pretty good. Is this not true? I'm somewhat overwhelmed with information and don't understand how to narrow down my search for the "right" diamond when everyone seems to give contradictory advice. Because it's expensive to have more than 2-3 stones sent to a local appraiser to see them for myself I want to do my best to pick a good stone from the numbers first. I just wish everyone would run the optical analyses and post them--I have a few stones from your site that I think are excellent, and I really appreciate the visuals (they help me to know what I'd be getting)
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I guess my next step is to contact vendors and talk to someone who knows more about diamonds!

Thanks for taking the time to respond!
 

valeria101

Super_Ideal_Rock
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Researcher...

I would think the range on numbers you consider is way wide to form expectations on brilliance based on it. If one degree of pavilion agle makes a difference in rounds, the situation is by no means better for these squares - just too many angles to consider for any HCA-like tool to be workable based on the usual cert (or AGA) numbers alone.

Even if EGL would not agree with GIA on this one, the price for the stone has more chances to be ok, and having a second opinion will help.

If you take a look on the Sarin and VirtualModels of GOG princess cuts, you will see that those princesses consistently come with table % just below the depth %. Whatever relationship works between crown and pavilion proportions, makes combinations of crown and pavilion cuts pass. The range of angles and depths is also workable from the couple' dozen stones with known light return scores.

I can't possibly claim authority in the matter, but your choice is clearly not in line with Jonathan's selection of princess cuts. And he has that Bscope and Iscope charts to prove his criteria sufficient but not necassary. Hope your stone reinforces the 'not necessary' part !
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Otherwise? Many enough would support the opinion that princess cuts are supposed to have large tables by design, to show the intricate sculpture of the pavilion and not all that much brilliance through the table.
 

researcher

Ideal_Rock
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Wow! And I thought I was getting a hang of this stuff! If I understand what you're saying, this stone will probably be too shallow--is that correct? I am seriously lost, and finding this whole process frustrating yet extremely intriguing.
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When I went to a large diamond super store last week, the stone that seemed to sparkle and be more brilliant than the others had a depth of 72 and table of 75. It's interesting because there were stones that had proportions that were much better (71 depth, 67 table).

The point is, I guess I'm not understanding the most important factors for a good cut. Is it better to have an overall cut grade of 1A or 1B with a table/depth/crown/pavilion that are given different grades, or to have a diamond with an overall cut grade of 2A or 2B with a table/depth/crown/pavilion that are all given the same grade? Does this make sense? I'm just trying to figure out how you know that:

"the range on numbers you consider is way wide to form expectations on brilliance based on it"

Is there a way to decrease the range? With AGA cuts of 1A-2A having a range of depths from 64-75%, is there a way other than keeping the table below the depth to determine which would work best?

If I can get the crown and pavilion angles will that give me a better idea of the stone's properties? Do you have any idea how I would know if the angles are good?

Thanks again for all your help! I'm blown away by the expertise of people on this site and your willingness to consult people on diamonds--I charge $350 an hour for consulting in my field!
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valeria101

Super_Ideal_Rock
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So... you might know what I mean saying that consulting is addictive
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and it does not need to be about things as nice as diamonds either.

Well, what you need is some too akin to the HCA, if brilliance really is the priority in your princess-cut chase. Unfortunately, there is not such thing yet, so either you look for some stone via Iscope (or direct tests of brilliance, not based o numbers), or get some educated guess of what proportions might work.

It sounds to me that you already went the second route. However, the AGA charts will not help with light return much. I wander wether the stones with all numbers within ONE AGA range actually have increased expectations for good light return - relaxing the constraints (so as to allow one charateristic to err and get an average AGA grade for the stone) does not seem to help.

All in all - the stones within the first three AGA classes would be desirable one for one reason or another, but both great and passable brilliance would largely be possible within the range (A1, B1, A2, B2 or whatever).

What could help then?
Two things: a nice database with stones known to be brilliant that one can run through and draw some criteria for a prediction (empirical reserach, right?)

OR

a model akin to waht HCA does (ray trace software and/or pen, paper and a couple of geometry and basic statistics books!) = teoretical model you feel good about.


Result? Hopefully one first good guess for a stone that has not already been spotted by a dealer (who likely already knows what you will be discovering) and inserted into his 'signature colection"/brand/selection with the premium for the type of 'value added' described above
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Does this make sense ?
 

valeria101

Super_Ideal_Rock
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Hm... this definitely did not take one hour !
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DiamCalc sells for about your hourly quote but would take many $350 hours to deal with....

So, why not line up your best four for PS to deliver it's usual $0.2 critique
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researcher

Ideal_Rock
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You are the best! Thank you for your assistance and wisdom--and especially your offer to take a look at other diamonds! I just got back from another diamond hunt expedition just to compare diamonds with similar specs and am now able to better see what I've been reading about. It's just funny when I go into the stores because I don't feel like I really know enough about diamonds, yet I seem to know more than the people selling them! What's worse is they try to pull the Rap Sheet out to show me how their diamond prices compare, and then I slap down my spreadsheet of diamonds and their specs from the vendors listed on pricescope. The expressions on their faces are priceless!

Changing subjects, what I have discovered in my search is the brilliance and fire of the diamond do seem to depend (at least in part) to having diamonds with tables, depths, etc. that fall in one range. I looked at one F VS1 diamond that was given an overall rating of 1B but had some variance and an F VS1 diamond that was given an overall rating of 2A with no variance in individual ratings and it performed much better
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Maybe it was totally random that this happened, but I'm now going to take this into account in my search. In fact, I found one diamond that I really like (except for the certification and color):

EGL
cut: 1A
color: I
clarity: SI2 (I think there are two feathers in the right hand corner, and one extra facet on the pavilion)
crown: 10%
pavilion: 55%
depth: 69.6
table: 65
ratio: 1.06
Girdle: STK
Polish: Good
Symmetry: Very Good
8.81x8.32x5.79
Fluorescence: No
Culet: No

Is this one better than the other? I don't mind the warm tones, but do worry a little about having it be actually yellow. If only I'd kept my search to the 2.0-2.3 range I never knew we could easily afford one so big!
 

Rhino

Ideal_Rock
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Messages
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Getting your tables lower than your total depths is a step in the right direction but still inconclusive (at least for me and when I'm about to drop my hard earned cash). A 10% crown height is good information to know but the key questions that beg answers at this juncture is what are the crown angles that constiture that 10% height and what pavilion angles are coupled with this? What makes this a little more complicated is various measuring devices report 2 different pavilion angles. One pavilion angle that runs from the culet to the corner and another that runs from the girdle edge midway down the pavilion slope. Some measureing devices give *both* angles but most only give one or the other. I like to know both but even then I *NEVER* purchase based on numbers alone when it comes to fancies.




Knowing the numbers however is only a preliminary screening on what may be worth or not worth your time for further investigation. Ie. If we like the angles/measurements I hear then I determine if that is going to be worth it to examine further and I limit my purchases to only those stones with the highest optical performance. Sometimes I can accurately determine this from the numbers (and I've got to know most of them) but many times there are question marks that can only be removed with a physical exam of the stone in question. There are vendors &/or appraisers who can help you in the hunt. Some of them post here and are very accommodating. Rich Sherwood & Dave Atlas are 2 appraisers who can. Not long ago a consumer here posted an example of Rich Sherwood's appraisal on one of these threads and it had an excellent report with pictures displaying the superior optical properties of the diamond he had purchased. Both I would highly recommend.




Regards,
 

valeria101

Super_Ideal_Rock
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The last stone 'sounds' very good. (definitely passes Rhino's "necessary but not sufficient quality" checks).

I-SI2 is up to you, but if the I color grade looks 'yellow' to you, than you're in trouble (same kind of trouble as Nicrez with her E rad). I like the description on those inclusion!!!

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Way back I used to make a simple analogy between colorless diamond 'colors' and the 'white' paints in a house improvement shop: you never know how many colors "white" is until you read their adds and know what to look for. However, this stinks: the shades of white in paint were meant to be seen, while the clasification of color grades in diamonds were such designed taht the ony people capable to identify them must have hands on experience and special conditions to work with. Othewise GIA would be a backyard lab not the monster information monopolist it is now!


Now... why do I get the feeling that the HCA was supposed to have a version for squares somewhere among the very initial plans ? I know princess cuts are not cut to such uniform parameters as the rounds (making that 'minor facets' talk a relative nighmare)... but still, it would have been fun
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valeria101

Super_Ideal_Rock
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And some wishful thinking
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... Since I am trying hard to see through those numbers, maybe you can help, Researcher: if my aritmetics is not completely off, this princess should have had a bright "X" pattern - with some light gone towards the mid of each side, but bright center and corners. Overall a very bight one, I hope. This is not at all unusual - but not a general rule of princes cut 'look' Besides, ray trace was definitely not ment for pen and paper: there is deinitely need for a shortcut!

Was anything like the pic below under your Ideal Scope ?

Wish.JPG
 

researcher

Ideal_Rock
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I haven't been able to see this specific diamond yet, so I don't know what I'll see (but I'll definitely let you know). BTW, I REALLY appreciate all your assistance! I wanted to make sure you know that even though I've said it before. I've really narrowed down my spreadsheet and am hoping to be down to my "top 5" by the end of the day so I can contact a vendor to send my "top 2" for me to make my final selection! I will post the specs by the end of the day....
 
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Hey Researcher:

I applaud you zest for learning about princess cuts and your desire to do your homework. I invested close to 6 months educating myself through pricescope and b&m places. I believe that I have one of the finest princess cuts available. Rhino from Good old Gold located it for me. Do a search on "Appreciative-of-expertise" and you will find a couple of posts that show the 3.03 princess that I chose, how the specs played out and a number of sarin, AGA, Idealscope...etc pictures to support what a stone should be. Check out the light leakage picture. The fires and scintilation that comes off of my stone is second to none.....email Richard Sherwood who did my appraisal. (Actually, do a search on my chronicle of working with an apraiser. - this whould give you some insite how an appraiser looks at a princess stone. Also check out the last page of my post "Chronicle of working with a custom designer - Mark Morrell". The pictures of the stone will validate what a good prncess should look like. Do not, I repeat, do not solely trust the David Atlas chart that is posted on this site. It is a good starting point; however, it should qualify that the brilliance, etc can not be solely predictedlike the stats for a brilliant round. Work with Rhino - he eats and lives this stuff daily online and in his store in NY. (princess cuts). HOpe some of htis helped.
Regards,

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researcher

Ideal_Rock
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Thanks for the tip, Appreciative-of-expertise!
I am definitely considering Good Old Gold for my final purchase. At this point I'm just trying to narrow down my search for the type of diamonds I'm liking and why so my boyfriend can have a better idea of what I'm considering when he contacts the vendors for the perfect diamond for both of us :) Oh, and before I forget, your diamond is spectacular! Congrats on finding an amazing stone!
 

oldminer

Ideal_Rock
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I am in the process of changing to a 10% minimum on princess cut crown height for 1A cut grading from the 9% that is listed right now. The crown height range will increase to 15% so possibly more stones, ones with more potential for brightness, will fit into 1A. The increasing number of princess cuts that can now be found in better qualities has increased our ability to quantify them as better performing. Credit a few good people who are promoting well cut princess cuts with sharing the details of these successful stones.

Things change over time. The more we know, the more we want to improve the sharing of information.
 
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Dave (oldminer), I applaud you for taking a step in the right direction. People like Jonathon and Richard S. would agree with that move; perhaps, would encourage more lattitude since that critical stat seems to play a key role in the livelines of a princess. I also encourage you to place a caveat on the fancy chart that reminds people that the stats are a good "starting point" but visual verification is key when it comes to these fancies. I know that you have reminded some people of that in replies to some posts but I fear that many, such as initially myself, will think that the specs on the chart will guarantee performance....Unlike a round stone where one pretty much knows what they will get once they see the associate specs.

Regards,
 

researcher

Ideal_Rock
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Dave,
I can't thank you enough for creating your charts and for your continuing quest to quantify diamond cuts. Because the internet provides consumers with so many options, your chart helps people to narrow their choices and know when a diamond should and should not be considered. As someone who makes a living on statistical analyses, I understand that their are people who will think of the numbers you provide as the difinitive answers and that is unfortunate. However, if they were to see the numbers you provide as the guideline you intended and use it to steer them in the right direction, I think everyone would thank you profusely for your contribution to the field (I was completely lost until I found your charts).

Thanks for all your hard work!
 

researcher

Ideal_Rock
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Here's another stone I'm interested and would appreciate your feedback on. I think it's more of a winner than the others I posted, but I'm not sure and was therefore curious what you thought before I go ahead and ask for more details/call it in:

GIA
Shape: Princess
Cut: 1A-1B (depends on crown/pavilion)
Carat: 3.05
Color: I
Fluorescence: Medium
Clarity: SI1
Depth: 69.7
Table: 67
Girdle: TN-STK
Polish: VG
Symmetry: G
Measurements: 8.18x8.16x5.69
Ratio: 1:1

Thanks for your help!!!
 

moremoremore

Ideal_Rock
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OH MAMASITA!!!!! DEFINITELY worth taking a look at....no guarantee, but that is a very good start!
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Call that sucker in!
 

valeria101

Super_Ideal_Rock
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The last two are clearly close contenders...

I do like the sound of "Very Good" symmetry in the first, but who knows? The "good" category is rather wide too.

At this point, inclusions could make the cut - the SI1 vs SI2 are not completely reassuring. Even a poor plot from the charts would be good, and pictures even better.

Is there any ay these could be compared?
 
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