shape
carat
color
clarity

How the number of chevron facets change the character of a princess-cut

Discussion in 'RockyTalky' started by Paul-Antwerp, Nov 7, 2006.

Thread Status:
Not open for further replies. Please create a new topic or request for this thread to be opened.
  1. Paul-Antwerp
    Ideal_Rock
    Trade

    Messages:
    2,825
    Joined:
    Sep 2, 2002
    by Paul-Antwerp » Nov 7, 2006
    I got the idea about this thread from a consumer''s thread, and it offers a great example how stones with a totally different character can both have ideal light performance and an AGS-0 grade.

    Because the cutting of rounds continues to concentrate around Tolkowsky-proportions, one hardly sees such differences in character in rounds, while in princess-cuts, in the absence of an historical ''ideal-set'', cutters have more liberty to explore different areas of high performance.

    Much of the difference in character is due to the number of chevron-facets in the pavilion. I am lousy at drawing and illustrations, so I hope that a colleague of mine will jump in and offer some illustrations.

    In the pavilion of a traditionally cut princess-cut, one tends to find a high number of chevron-facets. As such, the public might be used to a certain look of a princess-cut, which they find pleasing. Very often, this is refered to as a ''crushed-glass''-look, but it might be better to find another description, because this sounds rather negative.

    Now, it is possible, and you will find for sale also princess-cuts with AGS-0-grades, that have 4 rows of chevron-facets. With extremely high light performance, these stones will also have the character or look of that traditional princess-cut.

    On the other hand, one will also find princess-cuts with AGS-0-grades, where they only have 2 rows of chevron-facets. In total, this means 16 facets less in the pavilion. With similarly high light performance, these stones have a totally different character or look. Some people may like it, because it is bolder, while other dislike it, because it is not how they expect the look of a princess-cut.

    Of course, also 3 rows of chevrons are possible, and I suppose maybe even 5.

    Which look a consumer prefers, is impossible to predict. I know my personal preference, but you may have a totally different choice. And as far as my personal preference goes, it changes with the size of the stone.

    I just wanted to write this to make you aware of this important difference in look. Your preference depends entirely on your eyes.

    Live long,
     
    


    


  2. Lorelei
    Super_Ideal_Rock

    Messages:
    42,064
    Joined:
    Apr 30, 2005
    by Lorelei » Nov 7, 2006
    Thanks for this informative post Paul, I enjoyed reading it and getting an expert opinion regarding the variances seen in these shapes. Also that beauty is entirely in the eyes of the beholder or purchaser/ wearer.
     
  3. oldminer
    Ideal_Rock
    Trade

    Messages:
    6,269
    Joined:
    Sep 3, 2000
    by oldminer » Nov 7, 2006
    Paul , do you feel it would be best to grade the quality of craftmanship separately from quality or amount of light performance? Or, would you prefer the two "grades" to be combined?
     
  4. Paul-Antwerp
    Ideal_Rock
    Trade

    Messages:
    2,825
    Joined:
    Sep 2, 2002
    by Paul-Antwerp » Nov 7, 2006
    Dave, I do not understand the connection of your question with the subject of the thread.

    To answer your question, though, I do not know. Do you think that there is such a thing as accidental light performance, in which there is light performance, but no craftmanship?

    Turning it around, I definitely think that there are incidents where low light performance go together with high craftmanship. But is this kind of craftmanship graded, or even gradeable?

    Anyway, this is OT, and I do not have an answer for you, only more questions.

    Live long,
     
    


    


  5. Cehrabehra
    Super_Ideal_Rock

    Messages:
    11,071
    Joined:
    Jun 29, 2006
    by Cehrabehra » Nov 7, 2006
    I also hope someone posts some pictures or illustrations.... and I understand and agee with you on preference changing with the size of the stone. I haven''t put a whole lot of thought in which way I like my princess diamonds, but I''ve put that thought into LGF and diamond size. Some would rather have a hundred pinpricks, 50 thin splinters, or 25 thick splinters.... which is why I love my stone so much. As a funky cut I get the tiniest pinpricks, medium splinters, and big chunks. It''s a variety I haven''t seen elsewhere. I suspect in a princess I''d prefer a chunkier look because I like big fire, BUT I''m not so sure about that.... there are other cuts to choose, and those tiny little sparkles definitely are a flavor all their own and I don''t know what stone does it better than princess. So if you''re going to get a princess you might as well embrace it!
     
  6. Cehrabehra
    Super_Ideal_Rock

    Messages:
    11,071
    Joined:
    Jun 29, 2006
    by Cehrabehra » Nov 7, 2006
    I''m not paul, but *I* think they should be separate. ALSO I think the different numbers of chevrons should be labeled the same way I wish they''d manage cushions a bit better instead of having an endless array of cuts under one heading.
     
  7. JohnQuixote
    Ideal_Rock

    Messages:
    5,212
    Joined:
    Sep 9, 2004
    by JohnQuixote » Nov 7, 2006
    I''m not sure if this is what you had in mind Paul, but I made a few illustrations to simply demonstrate the differences in 2, 3 and 4-chevron Princess pavilion configurations.

    2Chev.jpg
     
  8. JohnQuixote
    Ideal_Rock

    Messages:
    5,212
    Joined:
    Sep 9, 2004
  9. JohnQuixote
    Ideal_Rock

    Messages:
    5,212
    Joined:
    Sep 9, 2004
  10. Paul-Antwerp
    Ideal_Rock
    Trade

    Messages:
    2,825
    Joined:
    Sep 2, 2002
    by Paul-Antwerp » Nov 7, 2006
    Thank you, John. I knew that I could count on you.

    Live long,
     
    


    


  11. JohnQuixote
    Ideal_Rock

    Messages:
    5,212
    Joined:
    Sep 9, 2004
    by JohnQuixote » Nov 7, 2006
    Appropriate observation. I'd also compare the differences to the different numbers of facets possible on round diamonds. It's possible to do single cuts with less facets than the traditional 57/58 facet round. We also see proprietary cuts with 60-some facets, 80-some, etc.

    In general, the larger the diamond the more it's possible that additional facets will appeal to the average person's eye. These things also depend on facet placement. As Paul appropriately stated in his first post, it is a matter of taste. Historically, cutters try to find a look that will appeal to the broadest range of people. That's one reason traditional configurations survive while proprietary cuts sometimes come and go.

    Of course, I'd also say it's also a matter of lighting. Someone who lives outside at the North Pole in a white parka in perpetual daylight months may prefer a different diamond than his brother, who lives in a cave with a gas lantern wearing dark clothes. [​IMG]
     
  12. JohnQuixote
    Ideal_Rock

    Messages:
    5,212
    Joined:
    Sep 9, 2004
    by JohnQuixote » Nov 7, 2006
    These are computer sims of 2 and 3 chevron configurations. They give an idea of differences when incorporating face-up reflections. Remember that these images are a kind of ''architecture art,'' in that they show what would happen in a diamond where all opposite facets are perfect twins of each other and every angle/line is straight.

    2-3ChevDialite.jpg
     
  13. Paul-Antwerp
    Ideal_Rock
    Trade

    Messages:
    2,825
    Joined:
    Sep 2, 2002
    by Paul-Antwerp » Nov 7, 2006
    Just for info, a single-cut round has 17 facets, being 1 table, 8 main pavilion- and 8 main crown-facets. Apparently, this is preferable on stones under 0.02 Cts. And I can still remember the era, when a 0.01 single-cut would cost about 25% more than a 0.01 brilliant-cut.


    I do not fully agree with your remark about cutters trying to find a look that appeals. In the case of princess-cuts, it is easier to hide weight if one has more chevron-facets. In the traditional way of cutting princesses of course.

    And very often, the fact of more facets is also used as a marketing ploy, without any reference to what appeals to the public.

    Live long,
     
  14. JohnQuixote
    Ideal_Rock

    Messages:
    5,212
    Joined:
    Sep 9, 2004
    by JohnQuixote » Nov 7, 2006
    Glad to help. You owe me a waffle. [​IMG]
     
  15. oldminer
    Ideal_Rock
    Trade

    Messages:
    6,269
    Joined:
    Sep 3, 2000
    by oldminer » Nov 7, 2006
    Paul, I was not trying to take you off topic. Sorry if you felt it was headed somewhere you didn''t want it to go.

    The number of facets certainly changes the looks and performance levels of diamonds even when they grade AGS 0 or have generally similar Sarin readings. I only wondered if you felt that grading the quality of craftsmanship would be a good thing to separate from the grading of light performance?

    I''d think people would care less about the number of Chevron facets, but would buy a diamond that looked great to their own eyes and judgment. Symmetry and craftsmanship are necessary to success of getting a beautiful stone, but the ultimate test is how a person feels a stone looks.

    Diamond cutters might get "accidental" light performance, but I doubt they would try to have any accidents due to the risk and cost. Of course, one sees low light performance with excellent craftsmanship quite frequently. It seems you feel there ought to be a separation of light grading and craftsmanship grading. This was my own thought and I believed it went well with the thread''s premise of a craftsman''s choice in cutting along with getting a beautiful result.
     
    


    


  16. JohnQuixote
    Ideal_Rock

    Messages:
    5,212
    Joined:
    Sep 9, 2004
    by JohnQuixote » Nov 7, 2006
    Historically I'm talking in terms of RB and princess cuts being the most popular - at least over the past 30-odd years - while other configurations come and go. Sure, there are 'new cut' marketing ploys. Fortunately the consumer gets to decide what is marketing and what has substance.

    Touching on the positive: There are also those dedicated to maximizing the beauty/precision of existing cuts as new tools and analysis come about. That's how consistent 'superideal' rounds evolved. Princess cuts are relatively young (evolving from Barion and profile cuts in the 1960s, for those interested). It was great to see the 2005 AGS light performance metric ignite some to strive, within that range, to find the best possible combination of visual appeal and economy for the consumer.
     
  17. Cehrabehra
    Super_Ideal_Rock

    Messages:
    11,071
    Joined:
    Jun 29, 2006
    by Cehrabehra » Nov 7, 2006
    I partially agree with this david - but if I already knew which pattern I preferred I''d likely request those same parameters. Like with a round - I know I''d want very short LGF unless the stone was like 4 carats. If I''d never seen any stone before, then no, the number would mean nothing to me. Once you have the info though, you can narrow the search down - I still think it''s important to list the number of chevrons, just like I think it''s important to list the LGF (and probably crown facet info - though I haven''t studied that *yet* hehe)
     
  18. oldminer
    Ideal_Rock
    Trade

    Messages:
    6,269
    Joined:
    Sep 3, 2000
    by oldminer » Nov 8, 2006
    Once we get complacent about what we believe we "prefer" we tend to stop looking at potentially better innovations. This is human nature and general to nearly everything, not just diamonds. Guys like Paul and John who are innovators and curious are a lot more fun to be around than staunch traditionalists. If the power houses of 1970''s diamonds were still in charge, we''d have no innovation at all. Instead, we have great waves of changes coming into the business creating degrees of confusion about where we are headed. Not all the changes will happen, but there is so much information we are struggling to know and accept the good while learning about and then discounting the bad.
     
    March-8-2008 likes this.
  19. Cehrabehra
    Super_Ideal_Rock

    Messages:
    11,071
    Joined:
    Jun 29, 2006
    by Cehrabehra » Nov 8, 2006
    I''m not saying we shouldn''t be innovative - just that if you know what you want, you should have the information that would weed it out available. I think it would be awesome if every jeweler had 31 flavors of diamond for you to choose from and then you could specify the other 3Cs. I don''t think that would limit innovation... there''s always room for 32 flavors. I dunno, I guess I''m a bit pragmatic in this because there is a certain romance in just blindly going in and looking at the diamonds and going THAT ONE but not having *any* clue as to why.
     
  20. oldminer
    Ideal_Rock
    Trade

    Messages:
    6,269
    Joined:
    Sep 3, 2000
    by oldminer » Nov 8, 2006
    Business decisions are far more complex than personal opinions or romantic accidents. It takes substantial planning to market a product with success. DeBeers has spent several fortunes on exactly that so you can have sufficient confidence to buy based on your emotions. Cutters and dealers must rely on financial reality, good planning and many other solid techniques.

    This good planning makes consumers feel like they can enjoy the experience and not be overly technical. I know that flies in the face of what goes on here many times, but most consumers are not at all technical in their buying of diamonds.
     
  21. Cehrabehra
    Super_Ideal_Rock

    Messages:
    11,071
    Joined:
    Jun 29, 2006
    by Cehrabehra » Nov 8, 2006
    debeers has spent several fortunes to convince us we need diamonds in the first place - and I don''t think it has given most (yes, even apart from ps) the confidence to trust many in the industry with their emotions. Some totally surrender and succumb, true... and some feel cheated and bitter, and some feel happy *enough* and some research, but I really don''t agree that inducing confidence in the diamond industry in general has been successful. On the other hand they truly have convinced us we need them *regardless* of our lack of trust. PS has done a good job of creating confidence, and by the same token more questions than answers have been generated as is true with anything - the more you learn the less you know...

    all of this good planning that you speak of seems to be a veil to say "just trust us" while at the same time the experts are saying don''t trust anything unless you have some numbers to back it up.
     
  22. oldminer
    Ideal_Rock
    Trade

    Messages:
    6,269
    Joined:
    Sep 3, 2000
    by oldminer » Nov 8, 2006
    Nearly all marketing is a veil to create the "just trust us" atmosphere. At PS we are teaching each other to know better.

    The more you learn, the more mysteries are discovered. This creates, in some of us, the desire to learn more still. Eventually we all get to a balance point where we believe we know enough. Right or wrong, we go on and find out eventually where our shortcomings still persist.

    Pricescope, for me, has been far more beneficial to the marketing of diamonds and jewelry than any other element of the business I've ever participated in. The open atmosphere is a welcome change from the existing alternatives of the past. I think an entire new generation of people who will want diamonds and jewelry will use the Internet as a wonderful resource for education and sometimes for the purchase, too. Some large and successful retail stores will be playing catch up for years to come. Hopefully, there is room for all good sellers to find their niche in the coming years. Its best to have many choices.

    Paul; Sorry to have veered off course again. How did we get here from Chevron facet count?
     
  23. Cehrabehra
    Super_Ideal_Rock

    Messages:
    11,071
    Joined:
    Jun 29, 2006
    by Cehrabehra » Nov 8, 2006
    we got here from chevron facet count because I said that I think it''s important to list the # of chevrons on the certs.

    As for the rest of your post... you have a point - though I am rue to willingly succumb to marketing as it goes against what I believe in to the core and focuses on the most superficial in our world in a most manipulative way. But hey, that''s WAY off topic and I''m sure I''m a hypocrite in some way about it anyway so we can drop that lol
     
  24. Paul-Antwerp
    Ideal_Rock
    Trade

    Messages:
    2,825
    Joined:
    Sep 2, 2002
    by Paul-Antwerp » Nov 9, 2006
    I disagree that there is a direct relationship (positive or negative) between the number of chevron-facets and performance. One can have fantastic light performance with 2, 3 or 4 rows.

    The difference is in look or character of the performance. With 2 lines, you have a stone with 20 pavilion facets, 3 lines give you 28 and 4 lines give you 36 pavilion facets. Imagine the difference in number and size of the virtual facets, created by this difference in pavilion facets. That is in some sense essential, and it might indeed be interesting for consumers to identify which look they prefered, and then to be able to find that information somewhere.

    I do not like the comparison with the length of the lower-girdle-facets in a round. Sure, a difference in this lenght might show a difference in look of a round, but that observable difference in rounds is way smaller than the difference, created by a different set of chevrons in a princess.

    Craftsmanship is a totally different story. Deciding on the number of chevrons is a strategic decision of the manufacturer-owner of the stones. The craftsman-cutter only has to execute the strategy. And there is no relation (positive or negative) between the number of facets and the level of craftsmanship.

    Live long,
     
  25. Cehrabehra
    Super_Ideal_Rock

    Messages:
    11,071
    Joined:
    Jun 29, 2006
    by Cehrabehra » Nov 9, 2006
    I don''t think we need to disagree because I don''t think there''s a difference (necessarily) in light performance between 2 and say 6 chevrons other than maybe a more consistent white with less obvious scint... I''m talking about the "flavor" also - and think it''s good to know this info so that someone who walks into a store and sees a pattern they like can say "yeah, I like 4 chevrons, can we go bigger/whiter/clearer?" I overlooked that last paragraph of David''s.. I agree that light performance should be apart from "craftmanship" though I hadn''t thought of it as craftmanship before. Coming into diamonds and quickly finding a love/hate relationship with cushions, I developed a love for facet placement and find GIA certs woefully inadequate in that department - particularly when you have helium and other instruments out there that could bind those facts right in at certificate level. My gripe with light performance issues in general is that everything seems to be pointing toward some single pinacle ideal that ignores other flavors... I think Garry with the BIC and FIC (should he fine tune this more) is on the right track to developing these flavors. I think that Princess cuts have the same opportunity in terms of fire and brightness AND in pattern flavor.

    I do think that LGF plays an equally significant roll if you look at extremes. A 2 chevron princess vs an 8 chevron princess.... LGF of 90 vs LGF of 40 (OEC like). These are facet pattern issues that play with the light already determined in "light performance". So on the one hand you ask yourself, "how much light return am I getting?" and on the other you ask yourself, "what are these facets DOING with this light?"

    If I were sitting at the round table with those that count in all of this, I would want, on every certificate, info on light performance (and when fire can be accurately measured and not just anticipated based on numbers) further broken down into white light/fire, info on facet cut (angles, true shapes, facets) to determine flavors, clarity including inclusion plots, finishing info (polish/sym) which to me is craftsmanship where facet cut is design... that''s all I can think of... and until I actually think someone cares what I think I''m not going to worry too much if I''ve forgotten something haha ;-)
     
  26. Paul-Antwerp
    Ideal_Rock
    Trade

    Messages:
    2,825
    Joined:
    Sep 2, 2002
    by Paul-Antwerp » Nov 9, 2006
    I do not think that we disagree on the light performance-part. I think that I disagreed with a small remark of Dave on this. And you are giving a nice synonym, by using ''flavor'' for what I called ''look'' or ''character''.

    If we compare the impact of LGF on rounds with the number of chevron-lines, I would say that the difference in ''flavor'' between 2 and 3 lines of chevrons in princess-cuts can be compared to the difference between 40 and 90 LGF-length. A difference between 2 and 4 lines is even more.

    So, we definitely agree on more than on what we disagree. (Weird sentence, I wonder if it is grammatically correct)

    Live long,
     
  27. Cehrabehra
    Super_Ideal_Rock

    Messages:
    11,071
    Joined:
    Jun 29, 2006
    by Cehrabehra » Nov 9, 2006
    Very glad to hear it!!

    Was thinking about this in the car on the way home - I''ve fallen in love with the science of diamonds at *least* as much as the thought of having my own to wear... I find myself feeling like I have a vested interest in these things (I really really think that every cert should have a helium scan right there so you can see the facet plot - take some of the mystery out of cushions in specific and others like how many chevrons on that princess as well) and that my opinion should matter LOL But in reality I''m just an opinionated consumer who''s learned way more than I ever needed to LOL!!!

    I am not fond of David''s use of "craftmanship" to denote quantity of chevrons any more than I would be for it to denote the various types of cushion. To me craftsmanship is about the quality of the work that is done which is most accurately reflected in what we call "finishing" ie pol/sym. To me the better those are, the higher the craftsmanship.

    The facet design is to me just that - design. You have basic shapes - round, cushion, square, rectangle, heart, oval... then you have facets... and we all know that one "princess" and another or one "cushion" and another or even one "round" and another (think solisfera etc.) will have different FACET DESIGN. I have become obsessed with facet design and to me that''s more overlooked than it should be - at least at the consumer level. ESPECIALLY with cushions, but I suspect with princess as well. Rounds they kinda name their proprietary cuts so you can usually find out more about why it looks a certain way (other than basic lgf issues) but anyway... more opinions of mine lol
     
  28. Rhino
    Ideal_Rock
    Trade

    Messages:
    6,223
    Joined:
    Mar 28, 2001
    by Rhino » Nov 9, 2006
    Greetings friends,

    Caught the convo here as I''ve subscribed to this thread but its been a little busy here so its been hard for me to break away. Here is a recent video you may find of interest I put together. Paul ... check this out. I think it captures nicely the broad vs pin flash effects seen between the 2 types of cutting in spot lighting and the contrasty difference in appearance in diffuse lighting.

    Peace,
     
  29. Paul-Antwerp
    Ideal_Rock
    Trade

    Messages:
    2,825
    Joined:
    Sep 2, 2002
    by Paul-Antwerp » Nov 10, 2006
    Hey Rhino, nice video.

    What was weird, when watching it this morning at home, the stone seemed very rectangular on the screen. Now, I watched it again, at ease, at the office, and the stones look very square.

    Anyway, it is a very nice illustration of a big difference. And here you were comparing 2 with 3 chevron-lines, where I guess that a huge number of princess-cuts will have 4 chevron-lines.

    Live long,
     
  30. oldminer
    Ideal_Rock
    Trade

    Messages:
    6,269
    Joined:
    Sep 3, 2000
    by oldminer » Nov 10, 2006
    Light Behavior folks, like myself, are definitely on the side of the consumer having factual data with which to help them find the "flavor" of what they most prefer. I imagine few will opt for the very highest measured perfomance as their tastes or budget may well dictate otherwise. Who is to say that the highest graded light performance will look prettiest? It certainly is not anyone I know. I hope this clears that matter up. In my mind there is no "pinnacle" of desired performance. It remains a matter of taste. We do have "engineer types" who demand maximum performance measures. Measuring light performance satisfies their specific goals, but it is a pursuit of those who place numbers above visual evidence. I cooperate with them, but please don''t think we are in that camp in our personal opinions.

    Cut Craftsmanship is partly symmetry and polish, but I include good design of the facets just like one would look at the appearance of a building to judge the quality of its architecture and not judge it by how well only the stucco was applied. There are many features of craftsmanship in diamonds that go beyond polish and symmetry. Since diamonds are costly, I really think part of craftsmanship is the creation of something beautiful, too. It is not a simple measure to grade craftsmanship, but craftsmanship alone, does not make a the entire image of a diamond.
     
Thread Status:
Not open for further replies. Please create a new topic or request for this thread to be opened.

Share This Page