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Crack in a 4.7k diamond


#1

I had someone asking me to clean a ring with an 4.7 karat diamond,
the stone on inspection had a big crack, you could not see it with
the naked eye, but clearly visible with a loupe.

It turns out, the ring was made smaller 5 years ago and I assume the
stone had not been taken out pre soldering.

She would like to have the stone ’ repaired ’ to avoid further
cracking.

Is there on the forum any one who could do a job like this? Or
recommend some one?

Preferable based in Greater London area, England or based in the
south of Spain?

Peter
Spain


#2

Oh feathers are natural cracks in a gem.


#3

I don’t know of anyone on Europe. The process is laser drilling a
hole then putting some Opticon into the crack. The crack is called a
feather.

John


#4
It turns out, the ring was made smaller 5 years ago and I assume
the stone had not been taken out pre soldering. 

Peter, it’s far more likely that the lady just knocked it on
something and cracked it but that’s neither here nor there at this
point. The people who fill diamonds on a large scale are Yahuda. No
doubt they have a website, but you may or may not find it easy to
get in touch with them. Otherwise I can’t say…


#5
The crack is called a feather. 

I’m assuming that owner would have known if the stone was pique, and
that something has changed…


#6
that owner would have known if the stone was pique, and that
something has changed..... 

I am not a native English speaker, (Dutch living in Spain, hence
karat instead of carat) I checked google but still have no idea what
the stone was pigue means! I assume that you mean the crack was
already there when she bought it? Maybe so, but is there a solution
for this problem? In Europe or what can I advise her? Can I still
clean the ring without risk?

What is the best method in this case?

Peter
Spain


#7
I am not a native English speaker, (Dutch living in Spain, hence
karat instead of carat) I checked google but still have no idea
what the stone was pigue means! 

Pique (q, not g) is an old fashioned (prior to the GIA diamond
grading system coming into widespread use) term for “included”,
meaning the stone as internal “feathers”, or cracks, included
crystals of diamond or other minerals, or other internal defects.
Usually the term means stones with fairly significant inclusions, so
they are visible to the naked eye.

I assume that you mean the crack was already there when she bought
it? 

Could be, and likely was, or could be damage due to accident of some
type. Sizing the ring is not likely to have caused the damage, with
the exception of stones that have been treated to enhance their
apparent clarity. That’s done by filling those cracks that reach the
surface, with a glass material that closely matches the optics of
diamond, making the cracks very much less visible. That type of
filling can concievably be damaged in sizing or other repair, if the
goldsmith gets the stone hot, as in “soldering temperatures”. This is
not common in ring sizing, but it’s not impossible either, especially
if the goldsmith was not as highly skilled as he/she should have
been.

Maybe so, but is there a solution for this problem? In Europe or
what can I advise her? Can I still clean the ring without risk? 

If the crack is very severe, you’re safer not cleaning it, but
instead referring her to some other jeweler with perhaps greater
experience with diamonds of this type. Just because the potential
liabilities of a stone this size should be considered. But in
general, most diamonds can be safely cleaned. The material is quite
tough, and withstands normal handling well.

Repairing the crack to prevent further cracking is not significantly
possible. It may be possible to have the crack filled, as noted
above, but this does not add strength or stability to the stone. It
just makes the crack less visible.

What is the best method in this case? 

Soak it in a mild cleaning solution (hot) for a bit, rinse it clean
(avoid the ultrasonic cleaner, and if you use a steam cleaner, do so
at a slight distance so the stone is not blasted with high
temperature steam), and give it back to her, advising her to seek a
jeweler who has formal gemological training in order to more fully
evaluate the stone’s condition and prospects.

Peter Rowe


#8

If it were me, I wouldn’t do a thing to it and I’d give it back to
her as soon as possible.

Liability is already there when you accept a piece. Thus before
accepting any repair it’s important to note any defects or issues and
have the owner sign a receipt saying so. Once the piece is in your
hands, it’s your word against hers as to whether the crack was in the
stone before or after it got to you.

One kind of scam has a customer come in with a piece with a
synthetic stone of some sort–ruby, emerald, sapphire, e. g.–and have
the jeweler accept it for repair with a receipt that describes the
piece as “ruby ring” for example. Then, when the piece is picked up,
the person claims that the jeweler replaced the stone and sues for
the stone’s value.

It’s important to note every feature of a take-in repair and have
the customer acknowledge the description by signing and dating the
note.


#9
but still have no idea what the stone was pigue means! I
assumethat you mean the crack was already there when she bought
it? Peter, the other Peter already answered some this morning, but
since this comes from my answer the other day..... 

As Peter said, Pique (pee-kay’) comes from pre-GIA and was used for
what is now called “I” clarity. There was 1st pique and 2nd and 3rd
piques. The term is still usedin the trade more casually to talk
about a stone that is heavily included, as in “The stone is
pique…”

Just to grab some numbers out ofthe air, if your 4.70ct. diamond is
J color and SI2 clarity, which is average or below, the Rapaport
value right now is $12,000/ct. or $56,400. I find it hard to believe
that your customer bought a fifty thousand dollar diamond without
knowing that it was included to the degree you mention. There’s a
high probability that such a diamond was certified somewhere
alongthe way, so one look at that document will answer all these
questions. If it wasn’t included to that degree then that means that
it has been damaged by someone, somehow. My mother knocked her
diamond against something and it cleaved a pie wedge out of the side
reaching from 1/2 way across thetop down to the culet in an instant.
It can happen, as any real diamondsetter can also tell you.

Although I don’t advocate paranoia, I doadvocate that if you feel
like work is beyond your expertise then you do pass it on to another.
As Peter said, there is no way to actually repair the stone, if it is
indeed damaged. Once cracked it is cracked and thereis no way to make
it whole again. Who’s liability that might be depends onthe
circumstances but as Peter largely agreed with, it is unlikely it
happened in sizing unless it was grossly mishandled. The caveat,
which Peteralso mentioned, is that if it was already filled then that
filler can be lost during high heat. If that were the case then this
would be in the cert, also.

The people who are in the diamond crack filling business are Yahuda,
who I link below. If you and the customer feel like you want to
explore that route then I will only caution that you need to be
inside the trade with credentials and ratings or they will refer you
to one of their retailers or perhaps just ignore you, frankly. Good
Luck…

http://www.ganoksin.com/gnkurl/ep80ns


#10

Big thanks to all your guys to help me out on this issue, special
thanks to John Donivan, Peter Rowe and Pedro online and off line.

Received excellent advise and have become a lot more knowledgeable
about this issue

I have together with the client decided to go for the acetone
solution, soaking for a few hours, followed with cleaning with mild
soap. She has acceptedthat the risk is all hers.

Thanks again

Peter
Spain