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How to Tighten Princess Cut Diamonds?


#1

Hello Friends!!

My question: How do you tighten a single princess-cut diamond in a
basic tiffany mounting? A lady brought one into my shop today. (I
generally send these to my competitors.) It had four straight 14K
white prongs (not V-prongs). Near the top of each prong a tiny hole
is drilled for the corners of the diamond. Pushing the prong toward
the diamond just results in spring-back. A jeweler friend of mine
suggested melting a little solder onto the top of each prong. Any
more suggestions??

Thanks in advance.

Dale Pavatte
Diamonds For You
Decherd, Tennessee


#2

Put your princess cut in the correct setting or you will pay for a
replacement when the customer looses it from an incorrect mounting,
your competitors will tell her that, shortcuts are not authorized by
true craftsman!

Stephen Wyrick, CMBJ
San Antonio, Tx


#3

Dale,

RUN don’t walk as far away and as fast as you can. Throw your
competitors some repeat liability jobs. Or sell her a proper setting.
Don’t even think about solder on stone points, solder shrinks when it
solidifies. Diamonds don’t shrink as much. Usual practice is to have
the very points in air, defiantly not imbedded in solder. A lesson I
learned long ago in the hard (but very permanent) way.

Jeff
Demand Designs
Analog/Digital Modelling & Goldsmithing


#4

I’ll second that, if the customer isn’t “dead set” against it, offer
to replace the (IMO) inadequate setting with one more suited to a
princess cut stone.

I have just delivered a cathedral style engagement ring with a 1
carat princess cut diamond, and I over ruled my customer wish to have
a four prong setting (I expect quite similar to what you describe) in
favour of a four pronged corner setting (similar to the H&S Tru-seat
range).

I’m very happy that I convinced him of the superiority of the
setting eventually used, stones are expensive and so is my time, so
if I don’t have re-do anything on this ring for a few years (I expect
I might have to re-size it or something one day down the track) I’ll
be all the happier!

Cheers, Thomas.
Janstrom Designs.


#5

Hi Dale;

My question: How do you tighten a single princess-cut diamond in a
basic tiffany mounting? 

You don’t. I’m very serious about this. Only an amateur, or a hack
taking a shortcut or going cheap, would set a princess cut in that
kind of setting, and you’d be foolish to attempt to make it work.
It’s loose because it’s the wrong type of head, and you won’t be able
to tighten it properly. Even if you get it to stop wiggling, it won’t
stay that way. You will, however, be able to bust a corner off of it
by trying if you push your luck. There are heads of that design,
Tiffany, that is, that are “V” pronged. I’m not crazy about them, but
they’ll work and are fine for smaller stones. A large stone, I’d have
other recommendations.

Now to address the idea of using solder to tighten the stone. That
might work (it’s a temporary solution at best), but it also might
break a corner off the stone. I’ve seen it happen with marquise cuts.
The prong expands with the heat, and a gap forms between the prong
and the corner of the stone. The solder gets under there and
solidifies. Then the prong cools and contracts, only now there isn’t
enough room so the metal pushes downwards at the tip of the point,
breaking it off. Probably wouldn’t happen with that head, since a
princess cut in that setting isn’t going to be held firmly anyway,
but it’ll be back in your lap before long when it loosens again. Tell
the customer that you’ll be glad to help them, but that this has to
be done safely and professionally and that’s the only way you
operate. Then tell them how much more secure their stone will be in
the new, appropriate head.

David L. Huffman


#6
Put your princess cut in the correct setting or you will pay for a
replacement when the customer looses it from an incorrect
mounting, your competitors will tell her that, shortcuts are not
authorized by true craftsman! 

Perhaps you’ve heard of Blaine Lewis’ video “The Art of Setting
Princess Cuts…”? In said video, you will find overwhelming
evidence to counter your claim that setting a Princess cut into
straight prongs is incorrect. For example, in the video, Blaine
actually cuts off two prongs (of an"incorrectly set stone") with a
separating disc and yet the stone does not fall out. It’s anchored
into the two remaining prongs because the bearings and ball pockets
were prepared “correctly” Even forcibly trying to push the stone out
of the remaining prongs is virtually impossible. It may be different
than tradition, but that doesn’t make it wrong.


#7

no one has mentioned that needle sharp points on a princess cut
diamond is a method of cutting for weight retention ! do we all know
what that really means ? if the girdle is extended to the point on
the princess cut corner then, that is faceting done by someone that
gives a rats ass about craftsmanship and quality

goo


#8

Hi Gang!

I just gotta chime in here and ‘set’ the course straight. You just
cannot adjust any simple claw head made for a round stone and insert
a Pincess stone…period!

If you wish to break the stone in this process go ahead…its like
saying you’re going to put a lawnmower engine into a Rolls-Royce
body…“but it still runs”…but the two don’t match up! Get my
drift!.:>) What’s the difference in price of these two heads?..about
a few thousand dollars!

If you look at the THICKNESS of the two heads or even the claws, you
will see one determining factor…Princess stones need and REQUIRE 50%
WIDER metal space…what for? so you can make certain angled cuts with
your bur ON EACH CORNER.You don’t have that luxury with a simpler
thinner claw.

The following process is needed. or there will be “Princess
diamond-dust” at the bottom of your bench tray. I do not jest here!

So you wanna just drill a little pilot hole? Well you got lots more
to do that that, trust me…once your corner holes are drilled to a
depth of 33% INTO the gold, you MUST then get your bud-bur and make
two side cuts from that hole, and horizontally to the left or right
of that hole. This is where the the two side girdles will sit, or
rest. I prefer a bud bur of only #006.

Then another grooving process with your same bud-bur from that hole
vertically downwards so the corner of the stone is not damaged when
it is sitting!..What I teach is that I bevel each of the lateral
grooves downward so the stone is not sitting on ANY sharp ‘seat’…IF
YOU DON’T FOLLOW THESE SIMPLE PROCEDURES, you are then going to be
looking for a ‘diamond re-polisher’.

So you’ve finished the grooving aspect of this process. Loosely
place the stone and using a 10x loupe making darn sure the diamond is
in the correct seating position of the claw/prongs.

SLOWLY bring in the claws so they touch the corners of the
Princess…do not hammer them in, don’t even tighten the two
’opposing’ claws at once…squeezing occurs here and also breakage.

As my good friend David Hoffman suggests, avoid the solder practice
like the plague. When the liquid solder hardens it leaves absolutely
no room for the stone to rest…total gold to stone. and there is also
shrinkage and a final “#$%%^&” woops! I personally love to set
princess stones.

The only reason for this “Pilot” hole in the center of a claw, is to
protect the corner of the stone. This is only that the stone will
not touch gold during the setting process and afterwards in the new
resting place…you can apply minimum side pressure, but NEVER to the
corner.

There should be a little space inside the claw between the stone and
the gold…Once this has been achieved, the rest is lots easy on your
nerves, and you can go ahead a file to your taste.

Gerry!


#9

My question: How do you tighten a single princess-cut diamond in a
basic tiffany mounting?

You don't. I'm very serious about this. Only an amateur, or a hack
taking a shortcut or going cheap, would set a princess cut in that
kind of setting 

I’m curious about this. My interest is largely academic, as I don’t
create or work with Tiffany settings, but I do occasionally use
princess-cut stones.

I took stone-setting with Blaine Lewis at the New Approach School.
One of the settings we did was a princess cut in a four-prong
setting. We cut a spherical opening in each prong to keep pressure
off the points, as well as cutting grooves with a graver where the
facet junctions would sit. Blaine demonstrated the strength of this
setting by pulling two opposite prongs loose, throwing the ring on
the floor and stomping it flat, then showing that the stone was
still held solidly in the two remaining prongs

The ring that we used to practice this type of setting was the exact
same four-prong setting we used for a round stone. Are you
master-jewelers saying this is dead wrong?

I recently created a piece in which I used two Tru-Seat princess
settings. I really did not like the look of the little "fish tail"
bits that folded over the top of the stone, though it was very easy
to set the stones in these settings. I much prefer the “ball” look
of the setting I did at New Approach.

So-- what type of setting are you saying should be used?

Thanks,
Noel


#10

This is about tightening Princess Diamonds? Boys and Girls don’t try
this at work! Yes I use me hammer hand piece on the flaps very
carefully and also will pinch the corners with needle nose. I also
use stone setting pliers to pull the metal on top of the stone.A lot
of princess solitares are set poorly. Having several stores to do
repair work,I tighten stones every day.

Time is Money!
Johneric


#11

Hi Dale,

Yikes! I would tell the client that her princess cut needs to be
reset properly, there should not be holes through the prongs.
Flowing solder around the point of a stone is a risky idea, the
molten solder expands a bit and can easily break the point. You can
do it, but it’s an unwise risk.

There is nothing at all wrong with setting a princess cut in a
standard 4 prong head, or setting it in a V prong head. Typically if
you use a standard tiffany style 4 prong head you will want the
heaviest version available so you have adequate material remaining
after you cut your seats.

If you cut your seat properly you can park the corners of the
princess cut right into the prongs with an airtight fit, you should
have no visible gaps. Certainly no actual holes. The point of the
diamond should be floating in space inside the prong, not touching
anything. That prevents risk of chipping. So if your diamond had
been set properly you should have been able to push down the prongs
slightly and tighten it up.

When we set them we start by drilling a hole for the point about
half way through the prong and about half the width of the prong.
You can use a twist drill or a ball bur. We then use a small bud bur
to open up the hole into a cone shape. Then select a 70 degree hart
bur that isn’t much bigger than the corner of the diamond and cut a
seat for the girdle that is perpendicular to the prong. Use the same
hart bur to cut a groove that starts 3-4 mm below the hole you’ve
made and continues up into the hole (this clears out the prong for
the keel of the stone). At this point you need to fit the stone and
adjust your seat for that particular stone. The angle of the seat
will need to increase to match the angle of the pavilion. The hole
in the prong will need to be hollowed out a bit more to be sure the
point is clear and safe. The point at which the groove for the keel
meets the hole will need to be softened to eliminate a risky
pressure point.

Once you start to set it, if you seem to be meeting resistance, stop
and pull the stone. Look at the seat and in the hole, if you see a
shiny spot that’s where the prong is hitting the stone. Go in and
remove the shiny area and proceed to set.

This is one of the many things discussed on this forum that is
really much better to demonstrate than to describe. If you really
want to lean how to do this I would suggest ordering Blaine Lewis’s
excellent CD. He does a fantastic job of both showing each step and
explaining the reasons behind the techniques.

http://www.newapproachschool.com/homeimages/princesscuts.html

I wish it had been available when I was first setting princess cuts
as centers so many years ago, it would have saved me a ton of time.

Good luck,
Mark


#12
In said video, you will find overwhelming evidence to counter your
claim that setting a Princess cut into straight prongs is
incorrect. 

It’s not the straight shape of the prong that’s the problem. It’s
the way the seat is cut. The OP described just a tiny drill hole.
That means a round hole, at least to me. So the hole, though it traps
the point, and would also prevent a stone from falling out in the
manner you describe in the rest of your post, does not equate to a
proper setting. There’s more to a secure setting than whether the
stone will fall out if you cut off two prongs. That’s actually easy.
More of a test is whether the seat not only holds the stone secure,
but is also holding it in a manner that protects if from damage in
the event of a blow. Usually that requires a greater width to the
prong than a narrow round wire, so the stone is supported by the
girdle to each side of the point, not the point itself. If the stone
is tight in an improper prong, just cutting off two prongs, or
pushing the stone, should be no more likely to loosen or remove the
prong than in a more traditional correct setting. But the incorrect
setting is more likely to result in stone breakage in the even that
one or more prongs is actually pulled back or loosened, which is more
likely to happen with straight or narrow or less strong prongs. And
as the OP observed, such a prong, once pulled out of position back
away from the stone, is much harder to tighten again correctly and
with safety because of the spring of the wire. A narrow straight
prong simply gives the stone less security, and is harder to
service. That doesn’t mean you can’t make a video showing it doing
wonderful things. I for one, have no trouble setting princess cuts in
plain simple straight up and down simple round wire prongs. Not that
hard. But I try to avoid doing so simply because the result doesn’t
look as good to me, and I know it’s not as strong and doesn’t protect
the stone as well. And when I DO set a stone in such a setting, you
can bet the seat for the corners is not just a tiny little drill
hole. That, as the OP has observed, is not likely to do the job very
well. It’s certainly quick, though, and you see a lot of that sort of
shoddy setting, especially coming from china and similar mass
production situations.

By the way, just because someone is a talented jeweler and teacher,
and makes wonderful instructional videos, does not automatically mean
that all their tricks and techniques are always the best way to do
things, or always correct. It means they are the means that
individual has found to work best for them, nothing more. Some of
what’s In Mr. Lewis’s videos is wonderful and cool and great
thinking, etc. Some other of what I’ve seen in some of them are
methods I have a significant argument with and which give results I
don’t like at all. To each his own. Just remember that just because
you see it in a video (Anyone’s video) or book (anyone’s book) or an
Orchid posting (Anyones…) does not automatically guarantee that
it’s always correct or the best answer. But you might keep in mind
that traditional methods and preferences, while not always up to
date and sometimes limited in imagination, etc, ARE traditional
methods simply because they’ve worked well over time, and for a lot
of people. That doesn’t mean they have no room for improvement of
course, but it does lend a certain authority to a method simply
through the time proven experience or many people.

Peter


#13
It's not the straight shape of the prong that's the problem. It's
the way the seat is cut. The OP described just a tiny drill hole.
That means a round hole, at least to me. So the hole, though it
traps the point, and would also prevent a stone from falling out in
the manner you describe in the rest of your post, does not equate
to a proper setting... 

I agree with most of your response, however my point (no pun
intended) was to challenge the assertion that settings other than
V-prongs are incorrect. And no, I don’t take whatever I
read/watch/hear from “industry leaders” as gospel. Not that you’re
entirely implying that, but I’m going to say it anyway. There is
certainly no better teacher than experience, but I’d like to avoid
as many headaches as possible by learning from others. Ironically, I
end up paying $$$ and time no matter how I continue to learn. Have
they invented that “learning by osmosis” machine yet? :slight_smile:


#14

after reading my post i realized i was not as clear as i could have
been about the P/C setting issue. the point ( no pun intended here )
is that there is more to this soloution than the skill of the setter
at issue here ! the cut of that diamond you are setting has somthing
to do with success and failure, it is not all about the prongs and
which head. a group of people can argue all year about which type of
prongs are right or wrong !

an issue i am bringing to the table is this, no matter which setting
you decide upon, If the girdle on that stone does not extend into
corner your risk of cleaving the corner off is highly increased.
those needle sharp points are there for the profit margin of the
diamond cutters ! think about it saving.01 cts on 100 diamonds = 1.0
cts my challenge to the list is this if you want to put the
situation in your favor, address the cut of that needle sharp point
on a princess corner to that diamond dealer.

the next time she/he tells you what a perfectly cut stone with a cert
they are trying to talk you into at a great price of 10% off the rap
sheet tell them they are full of it and that the stone isnt cut
properly and that my dear friends will ruffle someones feathers.

you will either see ablank look because they are clueless or the
dealer will get angry or nervous because theyve been busted.

How do i know this you ask ? well its because #1 ive made the
mistakes #2 i work with skip franklin who is a master cutter & # 3 i
now set P/C diamonds with great success in any setting i feel like -
later

goo


#15
The ring that we used to practice this type of setting was the
exact same four-prong setting we used for a round stone. Are you
master-jewelers saying this is dead wrong? 

Nah, I’d say it’s your basic rant. Those straight prong settings are
difficult to do well, and I suspect it’s more like a movement to
deter people from using them than any objective reality. If properly
set they work just fine, though I also dislike them. They aren’t
necessarily “cheap”, they have a nice clean look to them that many
people like, especially for earrings. I wouldn’t set anything over
1/4 ct. or so in one. It’s more like a V prong is the "traditional"
setting (like princesses have been around long enough to be called
that), and the straight prong settings are newfangled. There’s
certainly not any reason not to use them, assuming you know how to
set them properly, and the stones can be tightened IF they weren’t
butchered to begin with, which is likely if the stone is loose. I too
would never recommend one, as I like the v prongs for many reasons,
but the straight prong settings are not the evil ones some would make
you believe…

http://www.donivanandmaggiora.com


#16

Hi Noel;

I took stone-setting with Blaine Lewis at the New Approach School.
One of the settings we did was a princess cut in a four-prong
setting. 

Blaine has his reasons, and I respect his abilities as a setter and
a teacher. I’ve been setting for 35 years, and I’ve also been doing
repairs that long. I can imagine how he does it, but his theatrics in
that lesson point more to his skill as an educator than a setter. He
must have had the culet of the stone set down in the bottom of the
head to pull that off. Can’t imagine that looking very good: a little
squatty. And there’s another thing. There is a head that looks like
the Tiffany for a round, but it’s made for a princess cut, and there
are subtle differences in prong angle, thickness, etc. Again, setting
it in a round head can be done, but what’s the point if there’s
better choices? But I still think there’s problem with the basic
geometry of setting a princess in a head designed for a round stone.

Here’s what it is.

When you have 4 prongs as in a typical Tiffany setting, in the cross
section they are wider in one direction than the other. That means,
they can bend sideways more easily than they can outward. They lean
up at an angle that is pretty close to that of a diamond’s pavilion,
a little steeper, of course. When you cut notches in the prongs for a
round stone, the pavilion of, say, a 1 carat stone will make contact
with with about 2 millimeter’s of metal per each prong, and the prong
tip will bend over touching another 1.5 millimeters. Now, cut all
those notches and bend down the prongs, it’s very difficult for the
prong to bend sideways (which is the easier way for that cross
section of metal to bend). When the stone is locked down that way,
the top tip of the prong actually has to lift up a tad for it to be
able to bend a prong sideways. Not so with a princess cut because the
entire stone can rotate and change the relationship of the square to
the prongs. The top of the prong doesn’t have to lift, it only has to
twist a bit, which, because of that cross section, is easier than
lifting the tip of a prong. Rotate a round stone and nothing changes.

Are you master-jewelers saying this is dead wrong? 

In my shop, it’s wrong. Oh, I can set them like that, and I believe,
when I worked for others and they required it, I did that. But there
are plenty of heads that have the aesthetic of that classic Tiffany
head that are designed to do a superior job of holding a princess
cut. Just get out Stuller’s findings catalog and browse their setting
for princess cuts.

The thing about a proper head for a princess cut is that it should
have enough prong width to allow cutting a slight longitudinal notch
to accommodate that long facet juncture that goes from the point down
about half the length of the pavilion. And I NEVER rely on downward
pressure on the point of the stone to hold it. It’s actually held by
sideways pressure at the corners on the girdle of the stone. When you
bring the “V” in, it makes contact, then the angle of the “V” get’s
tightened and begins to fold over the top of the stone. With a
Tiffany made for a round stone, there is nothing to “squeeze” in to
hold that corner, you have to push the prong down onto the point,
which is dangerous if you put too much pressure on it, and there’s no
"vector" tightening possible because you can’t slide the prong
sideways, that means, there’s no way to compensate for that "bounce"
you get from the white gold.

Well, sorry to go on like this, but I suspect others on this forum
are going to blast me for this, so this is for them too. By the way,
if there’s anything you need done that Blaine Lewis does, just send
it to me and get ready to cut a check. I’ll match my setting skills
against his, but boy, if I were able to teach like that, I’d make a
lot more money and probably have a life too.

David L. Huffman


#17

Happy new year everybody.

Drew,

I don't take whatever I read/watch/hear from "industry leaders" as
gospel. 

you are so right about “industry leaders”.

Large part of my business is engagement rings and whenever a
customer asks for a princess cut I alway talk them out of it.

Princess cut, in my opinion, is an obscenity which has been
perpetrated on the public by the “industry leaders”. There is a cut
designed for low R.I. stones called Barion cut, which is basically
deep pavilion which enhances internal reflections. The lower R.I. the
steeper the angle. Princess cut is an extension of that idea, but in
case of diamond is does not improve the stone appearance, it simply
allows cutters to save material. It also introduces a lot of problems
for the jewelers.

The original post asks how to tighten princess cut in the Tiffany
setting. Tiffany setting was designed to allow light to reach stone
pavilion. While it is beneficial for brilliant cut, it does nothing
to the princess cut.

Let us understand the issues involved in setting of princess cut.

Princess cut is produced by taking an octohedral ( 2 square pyramids
joint at bases ) diamond crystal, sawing it in half and faceting each
half to produce 2 stones. Since no bruting ( rounding off ) is
involved and pavilion angle is closely matches native angle of the
rough, it is easy to see why the industry loves it so much.

Diamond cleavage direction is parallel to the octohedral face of the
crystal. Old timers in this business still remember the practice of
squaring the diamond which was done to avoid placing prongs in the
position to exert pressure in the direction of the cleavage. In
princess cut it is almost impossible. Whether one uses v-prong
technique or any other, there are only 2 choices, the direction of
force will be either in the direction of the cleavage or at 45
degrees angle to it. Using direction of the cleavage is not advisable
for understandable reasons. Using 45 degree angle means applying
pressure exactly to the corner of the stone, it’s weakest part. Not a
good solution either.

Princess cut could be set by devising a setting where stone rests
some distance below girdle and prongs should hug the girdle and come
down on the crown away from the edge thus avoiding the cleavage
direction, but it would look real ugly.

Leonid Surpin.


#18

I’m finding this princess cut setting thread truly fascinating. The
posts have been very informative indeed. As a novice, I’ve not yet
done any “high end” stone setting such as you get in a typical
engagement ring, but really want to have a go soon and am planning
to make some rings early this year just to have a go and practice
setting some inexpensive CZ’s. I’ve bought stone setting burrs and
have a full set of Gerry’s gravers so I’m looking forward to playing!

I have often wondered about the princess cut stone “wanting” to
rotate with relation to its prongs and wondered about the physics of
how they are set and so I appreciate this thread.

Keep the advice coming and happy new year to all!

Helen
UK


#19
Blaine has his reasons, and I respect his abilities as a setter
and a teacher. I've been setting for 35 years, and I've also been
doing repairs that long. I can imagine how he does it, but his
theatrics in that lesson point more to his skill as an educator
than a setter. He must have had the culet of the stone set down in
the bottom of the head to pull that off 

I’ve attended both of Blaine’s setting classes and having personally
set princess cuts in Tiffany mountings, I think it looks great. It
all boils down to what the customer wants, obviously. I do a lot of
trade work and it seems the big boys are having more and more
fancies set into common prongs. Whether it looks “right” is up to the
payee.


#20
The thing about a proper head for a princess cut is that it should
have enough prong width to allow cutting a slight longitudinal
notch to accommodate that long facet juncture that goes from the
point down about half the length of the pavilion. And I NEVER rely
on downward pressure on the point of the stone to hold it. 

David, I really appreciate the detail of your response. I think I
get it, mostly.

As for what you say about Blaine-- you are right, he is a fabulous
teacher, really exceptional.

I feel compelled to add-- the culet of the stone was not touching
the bottom of the setting. The whole point, as I understood it, was
that the notch for the corners of the stone was perfectly fitted,
with the opening in the prong cut in all four directions to fit the
facet junctions and girdle, and a nice ball-bur-cut opening to keep
pressure off the point of the stone. With this perfect fit, the
prongs hold the stone very securely and safely, even when abused.

I think it likely, in retrospect, that the heads we used for both
round and princess (they really were the same, I’m 99% sure) were
proportioned for the princess.

I will take another close look at the findings catalogs, but tell
me-- are you (anyone) happy with the way Tru-Seat princess heads end
up looking? Is there some way to finish off the prongs so they don’t
have the fish-tail-looking little flaps? They do save a lot of work,
but I don’t like the look.

I don’t use any prongs much, and when I do it is for colored stones,
and purchased heads more rarely still, but I really enjoy the way
setting brings my consciousness down to a whole new level of
miniaturization I never dreamed of before. Now that is attention to
detail! I actually began learning faceting, but have just not had
time to pursue it-- so now you know what kind of personality you are
dealing with.

Happy New Year, everybody!

Noel