Marquis diamonds break

Hello fellow jewelers! Just a quick statement of fact. Over the
last fourteen years I have seen approximately seven or eight
broken tips on marquis directly due to retipping; i.e., solder
at the immediate tip or tips. I have had this happen to me with
both tips breaking! The cast wk. head was hard and brittle. When
setting the stone the chev. end cracked. No biggie, I soldered
the crack and rebuilt the area presentably. When adjusting the
other end the same thing happened, and I consequently soldered
again. I delivered it to the store and made a Xmas customer
happy. Sometime after that the pressure of the cooled solder (I
suppose) cracked both ends. When the customer returned to the
store a few weeks later the damage was noticed and I ate it.
Lucky it was only a one-third. At any rate there are many
contemporaries unaware of this fact. Not to mention salespeople
quoting retips on marquis. I’ve done them since; quite
differently however (quote higher as well). I loosen or remove
the diamond prior to torchwork, insuring no solder around tip
areas. Let me know if this is more known than I suspect.
Thank you! Tim

Hello:

A very interesting situation. I would suspect that the mq. must
have been quite thin and/or the crystal grain ran parellel to the
tips. This would be the logical explination for your problem. Of
course, it’s also possible that the customer smacked the stone.
In eather case, I applaude your professional integrity in having
paid for the stone. I just hope it does’nt happen again!

Steve

Tim you are absolutely right. One should never retip on the
points of diamonds. The theory is that the solder get under the
tip and expands, thus breaking the diamond. We have not retipped
on points for years. We always replace the head or remove the
stone for repair. We had a series of damaged stone from this
procedure many years ago, and we changed our practice. It’s just
the way it is, if people don’t want to pay the extra repair cost
we return it undone, let someone else break it. Good tip Tim.

Mark P.
WI

Hello Steve! Hold your applause! I’ve long since forgotten the
cost of replacing the one-third marquis. I believe it was 82’ or
83’ My purpose in posting my message was not for consolation;
but to alert jeweler’s to this reoccuring problem.I’ve recently
taken a position in a guild store (oct. 98) and have seen two (
count them!) retipped marquis with damage already. Since my own
catastrophe as I stated I’ve known of a total of approximately
eight like problems. My frequency of seeing this prior to oct.
98 is less than a normal shop (i.e. repair etc.) having been
primarily involved in manufacturing since 88’. I guess I should
have worded my posting differently. My intention was as much a
warning as it was for discussion.

The two most recent broken marquis are described as follows: One
was approximately a 3/4 marquis with one chipped end. The style
was a cast bypass design that had two new ends installed. The
customer was having some other work done and the boss offered to
clean polish and appraise her ring and noticed the damage. The
(she was insured) diamond was removed (I was the jeweler) and a
fair amount of solder had flowed around (encased) the broken
tip.

The last was an old platinum filigree (probably 30’s) with
approx.11/2 ct. marq. with one broken tip. It had two side
prongs as well. The sales person had noticed the need for tips
and took it in for repair. The customer was not insured and
declined repair of the diamond. However, the prong work was done
(by me). Upon inspection I noticed all four prongs (two
chevrons) had been added too with white gold solder. Not wanting
to risk breaking the other tip (by soldering tips on)I removed
the diamond. I then fitted two “full” chevron prongs (platinum)
and just added platinum to the two side prongs; and reset the
diamond.

I’m hoping to get the word out to help others in avoiding what
appears to be a rather poor choice (retipping marquis tips) when
renewing marquis ends. The only ethical choice I can make is to
remove the marq. and partial or full prong and reset. I suppose
if it happened every time none of us would do it, but I think
it’s infrequent, and probably goes unnoticed for some period of
time. Hopefully I’ve explained myself better. You may recall a
trade shop in Seattle Olney’s J-Set (John Olney) he had also
experienced this problem. He retired and close his shop around
1988.

As a Diamond cutter this problem with the ends breaking on
Marquise diamonds was one of the most common reason for repair
next to girdle chipping. If you examine the ends and
particulally the girdle width most girdles are very thin and many
times not there and you have a knife edge, the same problem on
alot of princess cuts have at the points. Dulling these with a
scratch stick(diamond held in cement usually a small industrial
crystal) very carfully prevents chipping. But the flexing of
metal in rettiping on sucha thin material can do the same damage
as a heavy handed setter. After twenty years of cutting I would
just advise …Check the stone’s girdle befor setting…if thin be
very carful. Ron

Hey Ron, As a diamond cutter, can you tell us what we can do with
broken and burnt mellee? I have a several year supply. Some of
these stones cost as much as five hundred dollars to
replace…some around twenty. Just the same, it seems that the
best offer that I hear is to dump them for $35/ct. Major stones
I can have repaired for anywhere from $60-$150, No one I know
wants to touch the mellee.

Marquis madness! Back from 1979 through 1982 I owned a wholesale
repair shop. We never turned a job away. A marquis repair came in
with the stone set only by end V prongs. I cleaned it and
soldered new gold tops on the bars. It looked funny so I pulled
the stone out and it fell into two beautifully cleaved pieces. I
was shocked. I blamed myself for being careless. I even covered
the replacement of the stone. I placed the new stone into the
mounting and noticed a small thin spot from all the bending and
repaired it again. You guessed it, the same thing happened again.
What a really bad day. I have since learned that most of the
repair shops around here ALWAys pull any marquise out of a
setting before any soldered repair. I also have a question. With
all or many under one carat diamonds being cut by a machine, is
the grain of the stone ignored? Did the stones I broke have a
natural cleavage line exposed making them more vulnerable?

Best Regards,
TR the Teacher

TR, Most marquise diamonds cut into that shape are of two
pointer(two octahedral points in table) or four point(as in sawed
stones, with four octhedral points in table), and as far as I
know not many well cut marquise are cut by machine. The amount
of truma done to a diamond in the girdling(shaping) process and
then the faceting are usually more than any jeweler can or should
do to any stone. The orientation of the granular stucture of a
diamond does allow a stoneto break in a definable manner BUT
there has to be force whether it is mechanical or heating of
metal for the force to be great enough to chip or break a
diamond.

Most damage to broken Marquise diamonds look as though where
girdle is thin, pressure of prong movement, diamonds resting on
metal underneth in culet area, or just slipping with a tool.
Cleaving inhalf sounds very unusual unless it might have been
resting on a bulge of metal underneth stone and pressure was
applied. Then there also had to have been a flaw(feather) that
followed the cleavage line. I’d be very interested in more
details to give a better answer.

"The Force is within you, so force yourself" Harrison Ford "97" 

Ron Kreml

Hi Ron! Thanks for the info. I would only add that retipping, or
any solder around the tips has proven to also cause breakage. A
diamond cleaving from heat is something new, and probably
nothing we could prepare for. The luck of the draw I suppose. I
just set them and use ample time care.
Tim

Dear Ron, I wish I could have kept those stones for a closer
look. But as I recall the stones looked like they were sawed
right in half. The mounting was a Keepsake wedding set that held
the diamond in mid air. The V ends were the only thing holding
the stone in place. That style of mounting has always be a
problem for everyone. A good bump is bound to loosen up the
diamond. On lower end marquise goods I’m sure the stone or
stones will eventually come loose when just set with end prongs.
But that’s what a good jeweler is for.

Thanks,
TR the Teacher

Jewelry Dept.
Minneapolis Community & Technical College
www.mctc.mnscu.edu/acad/academic/programs/tech/jewelman/index.html

Todd, I know the setting you are talking about. Fortunately I
have worked with thousands of these and the key to setting the
marquis with the two V ends is contact with the upper gallery if
there is one or the mounting itself to keep it from twisting or
spiraling like a football. It works a lot better for keeping the
stone tight over the long haul.

Good Luck

Russ

Russ, The mounting I worked on had the stone mounted high
without the possibility of lowering it. Keepsake discountinued it
shortly after I worked on the ones I had problems with. Air born
marquise will forever be a jeweley owners (as well as bench
jewelers) nightmare.

Regards,
TR the Teacher