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Diamond cuts technicals


#1

Was: How to Tighten Princess Cut Diamonds?

I was under the impression that cuts like the princess, marquise,
pear, oval and the like were all modified brilliants, ie. designed
to maximise the return of light 

Tastes differ, so I respect your aesthetic preferences, but as far as
technical of the cuts, only round brilliant is optimized for light
return, the rest of the cuts were arrived at out of necessity.

I realize that it may an old school, but for whatever it worth:
Solitaire round larger then 2 carat looks obnoxious. If larger stone
is desired than oval cut should be used and after 12 X 8 it is
marquis to the rescue. Pears make nice earrings and pendants.

I do not understand them as a ring stone. Cocktail rings are
excepted from this discussion. But every sharp corner is a light leak
and there is absolutely nothing that can be done. Princess has 4 of
them and what makes it egregious that there is no need for it. Square
shape does not harmonize with human hand. It would make hand look
squarish which not complimentary to a woman, but may be o.k. for a
man. If woman wears long fingernails, the ring with square stone
would appear to cut the finger, not the preferred look. We very often
forget that client is not the walking display of our skills. It is
the other way around. Our skills should make the client look better.

Compare round brilliant and princess side by side. One condition.
Round brilliant should have table 53%, pavilion depth 43.5%, and
crown height 16.2%.

May take some effort to find it, but if you do, compare it to a
princess, then you will know what I am talking about.

My guess is that round cuts that you have encountered had very
different proportions, and deviations from them result in degraded
appearance. I even suggest that some of them were so badly mishandled
that even princess looks good in comparison.

Yes, I know that now it is more appropriate to talk about range of
proportions instead of rigid standard. I say hogwash! When we listen
to the music do we accept a range of a keys, or do we require an
exact match?

Leonid Surpin.


#2

Hi Kevin,

Helen, that's Leonid's personal opinion. It doesn't necessarily
have any validity in the world of aesthetics. Perhaps he's speaking
simply as a stone setter although 'obscenity' is a bit much. 

Oh I know it’s just Leonid’s opinion and I wouldn’t let that put me
off, but I think it’s a shame that someone would talk someone out
their choice of stone shape for such an emotional purchase as an
engagement ring for example. Yes, warn them of the problems involved
and that they may be faced with stone replacement/repolishing in the
future if they are heavy handed or offer an alternative, safer
setting for a princess cut but if it’s someone’s favourite shape
then I would try to accommodate that if possible.

Just my personal opinion.
Helen
UK


#3

I’m thinking if princess cut diamonds are so dodgy set in Tiffany
four claw settings, then why are jewellers selling them that way?
Customers looking for engagement rings usually choose from what’s
available in jewellers’ windows (unless it’s a custom piece of
course) so why not design safe settings?

I’ve probably got the wrong end of the stick again haven’t I?! Is
the original poster talking of taking in a repair on a ring made by
another jeweller who perhaps is just after quick bucks and repeat
business when the stone falls out or breaks? If that’s the case has
the customer been offered a different setting for their diamond in
the interests of saving money in the long run? It sounds as though
all the reputable high end jewellers on Orchid have a lot of repair
business from the quantity over quality type jewellers out there.
That must be frustrating sometimes when you may prefer to be making
beautiful high end and custom pieces rather than picking up the
pieces of people’s jewellery purchases that have gone wrong.

Mind you, before joining Orchid, I too was completely ignorant
regarding your run-of-the-mill high street jewellers with regards to
mass-production. I knew about diamonds and was well-read concerning
the four C’s but thought that jewellery is a luxury item and as such
all jewellers were selling high quality goods (as long as the
diamonds were OK). Now I’m a little more educated, I have a bit of a
giggle when looking in the chain-store jewellers’ windows and just
wouldn’t shop there anymore. Hopefully at some stage in the not too
distant future I’ll be able to make my own high end gold jewellery -
that’s if I can ever afford the price of gold! Maybe I should try
selling some of my silver jewellery first?

Helen (not able to crack open the JD as I’ve already finished it -
good job really as the diet’s started - Grrr! But enjoying my lovely
princess cut diamond ring from hubby for Christmas which is of course
calorie-free!) Preston, UK


#4
That's a shame, it happens to be my absolute favourite cut of
diamond. I'm not alone in this view either as most of my
girlfriends also share the same opinion. 

I sell diamonds. The average customer does not understand what they
are looking at unless they are educated about significant visual
characteristics of diamonds, and how the cutting affects these
characteristics. Unless you compare well cut diamonds of different
types of cuts, you cannot make a comparison.

A round brilliant has the same length of each pavilion facet from
girdle to pavilion. Pear, oval, marquise do not, so special care must
be taken when they are cut so the effect known as bow tie will be
minimized. All diamonds that are loner than they are wide have some
bow tie. Once this is pointed out, customers see what they previously
did not see. Quite often, once that is pointed out, that is what
jumps out when you see a diamond with a bow tie, and they are not as
attractive as they once were. Princess cuts have a darkness to them
at
the corners. If you compare a round brilliant to a princess cut side
by side, you will notice this. The darkness of the corners of a
princess cut detracts from the brilliance of the diamond. this might
not bother some people, but I do not like the look, and once I point
this out to my customers, they abandon the idea of princess cut in
favor or round brilliant, unless they are matching something they
already own that has princess cut diamonds…then I keep my mouth shut
about my prejudice.

The beauty of a diamond is the relationship of the white light,
brilliance, that is apparent from the light that is returned to the
observer from the top, or table facet, and the dispersion that is
light
that returns from the crown facets. Quite a lot of princess cuts have
little to no crown facets, so you get brilliance but no dispersion.
Not attractive to me, too flat looking. If you ever want to see
magnificent diamonds, find a way to see a large emerald cut that is
radiant cut. Done right,those are most impressive, and my opinion is
that anyone who says they do not like diamonds have never seen
anything like that, because there is nothing to not like. The
dispersion of a large diamond makes happy in your eye.

If you look at old mine cut diamonds, where they cut a facet on the
pavilion of the diamond, you will notice that the center of the
diamond looks dark, as the light is leaking out of the diamond. That
is one of the best ways to show how cutting affects the beauty of a
diamond, show a mine cut next to a standard round brilliant and it is
readily apparent.

Richard Hart


#5

H - what makes princess cuts so bad to set is the uncraftsman like
way of cutting the girdle.

if the girdle on that princess cut does not meet all the way at the
point its dangerous territory. you can see the more beneficial way
more easily on colored stones. mostly on diamonds the girdle facet
stops a tiny bit before it gets to the tip,point or corner. when the
girdle on the diamond does not extend up to the point or corner they
tend to shear off very easily mostimes it will cleave from girdle
most of the distance to the culet. i am confident its done to save
wieght (.01 ct on 100 stones = xtra profit ). the diamond dealer
doesnt like to hear that thier GIA certed E VVS 1 w/needle sharp
points is an accident waiting to happen they are banking on your not
being hip to whats up w/ pointy corners

goo


#6

Hi again Leonid,

I don’t want to get into some silly argument about our personal
preferences regarding princess versus round brilliant cut diamonds.
It is just that our own personal preferences.

Don’t get me wrong, I adore a good round brilliant diamond, they are
beautiful without question but for some reason, myself and many
other women love the princess cut. I love the arrangement of facets
and princess cuts, like round brilliants look rubbish when included
and beautiful when clean to the naked eye.

I have seen top quality round brilliants as a friend’s dad is an
independent high end jeweller and so when my friend got engaged, he
commissioned his dad to make the engagement ring. I can’t remember
the spec off the top of my head but let’s just say the diamonds are
simply intoxicating, you couldn’t stop looking at them. I’ve also
seen top quality princess cuts and rounds at trade shows so know
what you are saying, but I still like princess cuts.

I understand what you are saying about in a ring also. I love
rounds, marquise, pear, oval in rings and yet princess is still my
favourite and I can’t explain why. Sorry for being stubborn.

Helen
UK


#7

Yes, I know what you are saying Richard. Leonid also pointed out the
same, but I have seen top notch diamonds next to ordinary diamonds
but I know what I like. The beauty of a diamond is “the relationship
of the white light, brilliance, that is apparent from the light that
is returned to the observer from the top, or table facet, and the
dispersion that is light that returns from the crown facets” to you
because that’s what you were taught. That doesn’t mean that that is
the definition for everyone. Beauty is in the eye of the beholder
after all. You cannot tell me or anyone else what to like. I like
what I like. Yes I could walk into a good quality independent
jeweller’s shop and be shown diamonds side by side and be told what
you have told me but I don’t like what people tell me to like. I
like what I like simple as that.

Just because I am new to the world of jewellery making and still
have a vast amount to learn, doesn’t mean that I know nothing. I know
what shapes I like and don’t like. I love: round brilliant, oval,
pear, marquise, emerald/octogan, trillion, barion, radiant and of
course princess and probably a few more that I can’t think of off the
top of my head. I hate: old mine (very ugly indeed), Asscher, heart
and again probably a few more. My tastes are instinctive and don’t
tend to change dependent on what someone tells me.

When shopping for clothes (which incidentally I can’t stand doing
and would rather do it online), if something jumps out at me in the
first shop, and I love it, I buy it and go home. I will NOT troll
through shop after shop “just in case I see anything better” because
every time I’ve done that on the insistence of my sister for example,
I NEVER find anything I like more and end up going back to the first
shop to buy the item I liked initially - a complete waste of time.
The same goes for diamond shapes and whether or not I like a piece
of jewellery. If I like it I’ll always like it. If I don’t I never
will.

This is getting a pointless argument which is one of pure taste and
personal opinion btw.

Helen
UK


#8
I was under the impression that cuts like the princess, marquise,
pear, oval and the like were all modified brilliants, ie. designed
to maximise the return of light 

Having cut stones for 37 years now, I’d like to throw my ten cents
into the ring, in the spirit of education.

The above statement is at least half true, maybe more. As is common,
semantics may lead us down a muddy road.

Before speaking broadly about cuts, we must make or state some
assumptions. For our discussion, let’s assume that when we say
"round", we are referring to what we commonly call the Standard
Round Brilliant with which we are all so familiar. There are many,
many other cuts that can be performed to produce a round shape, but
it’s uncommon to see them in diamond, and let’s stay with diamond
here for this discussion.

The “brilliant” style of cutting refers to the design of the facet
arrangement on the pavilion of the stone, not to how bright the
stone may or may not be. A “brilliant” style is one in which the
"Main" facets reach from the culet to the girdle. The only other
facets on the pavilion are the “Breaks” or “Lower Halves”.
Currently, the fashion is to cut the stone so that the breaks run
about 7/8ths the distance from girdle to culet.

If we take this facet arrangement and simply stretch it in one
direction, we will be creating the “Oval Brilliant”.

If we stretch only one side of the round and bring the facets to a
point, we will have created the “Pendeloque”, commonly referred to
as Pear Shape.

Pulling the fat end of the pear to a point makes a Navette shape,
commonly but incorrectly called a Marquise shape. Strictly speaking,
in cutter lingo, a Marquise is a Navette shape with strict and exact
2:1 proportions (Length is twice the width).

The traditional square shape in diamonds is a “step” or “trap” cut,
all facets running parallel to the girdle. The pavilion may have two
to seven “tiers”, but usually 3-4 and the matching crown has 3,
usually, but not necessarily. The usual practice is to cut the
corners of the square to avoid possible damage to the sharp corners
in handling or setting. Although the corner cuts are usually small,
exaggerating them leads us in the direction of the traditional
Asscher cut, a patented (these days) design when performed in
diamond, but not when performed in color. It’s spectacular in light
to medium colors, by the way.

Princess cuts are another square shape, by definition, with a
pavilion facet arrangement completely unlike any of those mentioned
above. While a true Princess or the similar Quadrillion cut have
very specific facet arrangements, many variations exisst, some of
them quite attractive. As far as performance when compared to a
well-made round brilliant, a well-made Princess or Quad mets or
exceeds the brilliance return of the round. Variations away from
being “well” made are obvious and performance of the stone falls off
rapidly. Performance holds up better for rounds when slight
variations from “ideal” are made. But, to be clear, Princess,
Quadrillions and especially square Barions meet or exceed the
brilliance of rounds.

When the corners are cut on a Princess shape, at least eight facets
have to be added to bring the girdle to a level condition, and,
strictly speaking, a “cut-corner princess” is no longer a Princess.

Radiant cuts are squares with cut corners that have another entirely
different facet arrangement from Princess, and their performance,
too, is as good as a round, when they are cut to the proportions
that bring them to full life.

It’s wise to remember that brilliance is not always the goal. The
most spectacular diamond I have ever seen was very large "Emerald"
cut. In that size, when done properly, the dispersion is absolutely
stunning in sunlight. So, we all have preferences.

It is possible to create a “marquise” or oval shape or even a pear
shape without the noxious “bow-tie” shadow we see in the standard
cuts, but the diamond business is entrenched in tradition,
unfortunately. Fortunately, we who cut color are not restrained by
tradition.

I have had clients who returned gifts of diamond jewelry. Two stand
out. One was the wife of a very hard working man who had risen from
poverty to multi-millionaire status in real estate acquisition. He
wanted to replace the 0.15 c wedding ring his wife had been wearing
with a 3.8 carat of very high quality. She returned it saying that
it was not what she had gotten married in and nothing was going to
replace THAT ring (!), and, besides, it was gauche and she did not
wish to embarrass her friends with so large a display.

The second was return of a 4c TW apir of diamond earrings (2 c
rounds in each ear), because he client felt they were too
ordinary…larger please, like 4 c each (!). So, who knows?

Wayne Emery


#9

While we’re on about Princess cuts…has anyone else noticed that
princesses sometimes face up whiter than they actually are? I don’t
know the reason for this but its something to keep in mind if you buy
mounted stones.


#10

Hi Goo,

Thanks for your reply. It’s an informative reply without you telling
me what to like and what not to like - as some others have done, so
thanks.

I have recently bought a job lot of cubic zirconia in various sizes
and shapes and all are really beautiful but I was disappointed to
find that the princess cut stones all had fairly thick girdles
continuing right round the corners, but now some of you professional
setters have extolled the virtues of having such thick girdles on
princess cut stones, and also having broken the corners off a few
princess cut stones myself (not the ones with thick girdles), I’m
chuffed to bits with their proportions. And when it comes to buying
some princess cut diamonds in the future, I will now know what to
look out for. The physics of what you say makes sense regards
security of setting.

But I still love their aesthetic appeal.

Helen
UK


#11

Personally, I’ll say that the “discussion” (rant) against princess
cuts is pretty out there. Don’t sell them. Done! Anyway, I’ve posted
this, I think, before, plus it’s on the links page of our website.
The Russians came up with a modeling routine that raytraces actual
light through actual diamond - on a computer, that is. It’s quite
fascinating. Under “cutting” you can change the diamond shape, play
with the angles, and hit “play”. And you can play with the
proportions as it plays, too. Have fun!

http://www.cutstudy.com/cut/english/coll_rays.htm


#12

Helen what makes princess cuts so bad to set is the uncraftsman like
way of cutting the girdle. if the girdle on that princess cut does
not meet all the way at the point its dangerous territory. you can
see the more beneficial way more easily on colored stones. mostly on
diamonds the girdle facet stops a tiny bit before it gets to the
tip,point or corner. when the girdle on the diamond does not extend
up to the point or corner they tend to shear off very easily mostimes
it will cleave from girdle most of the distance to the culet. i am
confident its done to save wieght (.01 ct on 100 stones = xtra
profit). the diamond dealer doesnt like to hear that thier GIA certed
E VVS 1 w/needle sharp points is an accident waiting to happen they
are banking on your not being hip to whats up w/ pointy corners

goo


#13

Wayne,

Thank you, thank you, thank you! When I made the statement about
princess, marquise, pear, oval, etc being modified brilliants, I was
referring to the pavilion facet arrangements and you have confirmed
this with regard to navette, pear and oval.

I did not wish to get into some silly argument about personal
opinion. It’s refreshing to read what you say about well cut
princess diamonds and quadrillion outperforming a round brilliant in
terms of brilliance or light return. I’ll look into the qualdrillion
as an alternative but still love the princess.

I was advised to look at the Flanders cut but to me it too closely
resembles the round brilliant. I prefer the look of the square
radiant and Barion cut but will also look at the qualdrillion.

Any more suggestions for alternative square cuts which exhibit a
similar star-shaped arrangement of facets to the princess cut would
be gratefully appreciated.

BTW I’m with you on the emerald cut diamond too. Fantastic
dispersion and flashes of light.

Helen
UK


#14

Hi again Wayne and all,

I looked at the Quadrillion. I like it, like it, like it. It has
everything I like in the Princess cut but shares the brilliance of
the round brilliant. See following website:

http://ambardiamonds.stores.yahoo.net/quad.html

Perhaps I’m just awkward though. In the first picture, the one of
the Princess cut, I actually like the contrast created by the black
areas. We all like different things in life. Good job really!

I’ll probably continue to favour the princess cut as anything
slightly out of the ordinary adds too much onto the price and
diamonds are expensive enough already.

Helen
UK


#15
Don't sell them. Done! 

Precisely!!! I will continue to buy them and love them. I love
Princess, square radiant, and now after its recommendation,
Quadrillion. The jury’s out on Barion but I can’t stand the Asscher
cut. Open to suggestions for suitable alternatives to the Princess
as long as it has the star-shaped facets on the pavilion.

But each to their own. Buy, set and sell what you like and don’t
buy, set or sell what you don’t like.

Helen
UK


#16
As far as performance when compared to a well-made round brilliant,
a well-made Princess or Quad mets or exceeds the brilliance return
of the round. Variations away from being "well" made are obvious
and performance of the stone falls off rapidly. Performance holds up
better for rounds when slight variations from "ideal" are made. 

Excellent point. Any cut executed by a professional who understands
plusses and minuses of a particular design will result in a beautiful
stone. So those who are princess cut aficionados, well advised to
search for custom cut stones.

Leonid Surpin.


#17

Helen,

You cannot tell me or anyone else what to like. I like what I like.
Yes I could walk into a good quality independent jeweller's shop
and be shown diamonds side by side and be told what you have told
me but I don't like what people tell me to like. I like what I like
simple as that. 

Never in my post did I tell anyone what to like or not like. I just
explained characteristics of how light is affected by cutting. I
never try to steera customer toward or away from a particular cut.

Some customers come in asking about princess cuts. I show princess
next to round so the customer can see the difference. Some people
like
the princess cut, but some upon seeing the difference choose round.

If a person came in asking for a round brilliant, I would not show
them a princess cut for comparison. I have never seen a princess cut
that did not have a darkness to it that added to the visual beauty.
That’s my perception and my opinion.

Something that has not been mentioned, the trilliant, or any cut
that is based on 3, 6, 9 pavillion mains return the most light. Just
physics.

Some people are not as sophisticated as you are and are quite
grateful for the I provide that helps them make an
informed decision. Some people think they know what they like, but
for
some reason once they have a better understanding of what they are
looking at, their opinion changes.

Richard Hart


#18

My opinion is that most diamonds are not cut well. Comparing a round
brilliant with a princess cut, in my opinion, a poorly cut round
brilliant looks better than a poorly cut princess diamond. My opinion
is based on the diamonds in the jewelry that my customers bring in
for redesign and repair.

Richard Hart


#19

Hi Neil;

about Princess cuts...has anyone else noticed that princesses
sometimes face up whiter than they actually are? 

I don’t know about princess cuts perticularly, but I’ve noticed that
effect in larger stones in general. I just worked on a ring with a 2+
carat round that, when mounted, looked, face up, like an I color or
better, but it wouldn’t stay that way. I couldn’t pin it down. When I
pulled it and flipped it over on a piece of white paper, you could
see how yellow it was, a J or worse. Even so, it wasn’t that way
under all light sources I noticed. Next time you get a large stone
that’s looking different colors under different light sources or from
different angles, try this. Lay the stone, mounted or otherwise,
table facet down on a small LED flashlight that’s on. You’ll get a
surprise. Hope some GIA folks here can explain all this to us “seat
of the pants” diamontologists.

David L. Huffman


#20

i just wanna say my two cents with richard, i agree that most stones
in general are not well cut, which is why when i find a stone that
is high priced comparitively i ask what is the cut. usually the
higher priced stones are

well or at least moderately well cut.

just my opinion.
ken