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Testing diamonds for fracture filling


#1

During shop talk someone stated that fractures that come to the
surface cannot be filled. It was my perhaps erroneous understanding
that only surface breaking fractures could be filled.

Thinking more about it I can imagine laser drilling to get to the
offending inclusion, opening a conduit for the filler, leaving a
drill hole that presumably gets filled too, in the process. But this
is just conjecture on my part.

So…if a lasered hole can be filled, why can’t a naturally
occurring surface opening be filled? Not talking about a cavity, just
a fissure that meets the surface. Or is this someone mistaken?

And then further on, the question of durability came up but with a
twist. Suppose a filled diamond had been torched, eliminating the
filler. Customer did not know it had been filled and assumes the
jeweler switched or damaged the stone. Is there a gemological test
that could determine conclusively that the diamond had been
previously filled?


#2
Is there a gemological test that could determine conclusively that
the diamond had been previously filled? 

If you rock diamond under the microscope or even a loop, you would
see the flash of color. Polarized filters can help.

But the most important point is fracture filling does not effect
clarity grade on a cert. So if you see I1 but it looks like VS1, you
have got a fracture filled stone.

Leonid Surpin.


#3

Well, this is the reason for a careful, careful take in process and
identifying the fracture filling first and making sure the client
knows about it. Sometimes husband knows, wife doesn’t.

It is not hard to identify, once you have seen it once.

Elaine
http://www.CreativeTextureTools.com


#4

Good question i am going through this with a customer now he brought
in a three stone ring needed a couple prongs retipped no big deal.
But now try to convince him you didn’t ruin his diamonds. We did
convince him now we remove the diamonds send to one of the companies
that make them and will fix for free. Still something that should be
a simple repair turns into mess. It would be great if there was a
simple test.

Dwaine


#5

Hi Neil,

I believe your understanding to be correct. The fractures must be
surface reaching to give the filler a way to get in. The filling can
typically be spotted by looking for a flash effect. Look at the
diamond under magnification from all directions and rock it back and
forth. If a fracture is filled you will see two colors flashing as
you rock the stone. Colors you might see are yellow to orange,
pinkish purple to yellowish green, or yellowish orange to strong
blue. Fiber optic light can help make it more visible. The flash
will be a clear two color change though and should not be confused
with the rainbow iridescence that can sometimes be seen on an
untreated fracture. You might also look for bubbles trapped in the
filler or crackled texture in the filler.

Most laser drilling I have read about, the drill holes are just left
there and are not filled. I assume they could be filled though.
There is drilling done from the surface to a dark inclusion inside
the gem. Acids or bleach are then used to lighten the inclusion. All
this has now created a new clarity characteristic in the gem but it
is preferred by some as it is all whiter and does not stand out like
the darker inclusion, making the diamond more marketable. There is
also laser drilling done on the interior of a diamond which does not
leave a drill hole that reaches the surface. The laser rather
expands the inclusion and causes a cleavage to reach the surface so
acid/bleach can then be introduced.

Identifying filled diamonds is very important for jewelers, like the
repair scenario you described. And for appraisers too. Look for the
flash!

Hope that helps-Carrie Nunes


#6
Is there a gemological test that could determine conclusively that
the diamond had been previously filled? 

I’m not a gemologist, but I have a method to determine if they have.
I look at the stone (after I clean it well) under a microscope and
slowly turn it back and forth, left to right & vice versa in search
of an orange ghosty thing.


#7
It would be great if there was a simple test. 

There is. Just look at it under the microscope, you can see it. This
is something I used to do when I worked as an appraiser.

Elaine
http://www.CreativeTextureTools.com


#8
But the most important point is fracture filling does not effect
clarity grade on a cert. So if you see I1 but it looks like VS1,
you have got a fracture filled stone. 

are sure you about this ? perhaps my memory is not so accurate but i
think yehuda grades thier stones after they have been filled i had
one a couple of years ago that was clarity graded SI-2 and definatly
looked like SI-2 - goo


#9

I don’t agree with this statement. if you see I1 then it is I1. How
can it look like VS1. All grading, according to the GIA, is done at
10X through the table by someone trained in this field. The key is
that it is graded by someone trained in the field. Someone later on
in this thread wrote about an orange ghosty thing. It’s called the
flash effect.


#10

Rocking and looking for the flash in fracture filled stones is fine
and dandy if the filling is still there, but I believe the question
was, if the filling has been burned out through torch heating is
there any way to prove that the stone used to have fracture filling.
Not sure I have an answer to it.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
1780 Massachusetts Ave.
Cambridge, MA 02140
www.spirerjewelers.com


#11

I have seen a number of stones with a purple, blue or pink flash
effect. Usually not visible from the crown. I believe that this
effect in not inherent in the treatment. I believe that it is added
to aid in it’s detection.

A story.

Some years ago, I was asked to set a diamond in a stock mounting.
After I started, I found that this particular pendant really need
some unwanted prongwork. After applying a torch, I noticed an
unusual amount of staining. After trying to clean it, I decided that
it must have had some fracture filling that had been previously
unnoticed. Yup. The store owner was caught unaware and furthermore,
his dealer had been caught unaware. None of us had noticed. It may be
that each of us. in turn, trusted our source, so we had let down our
guard.


#12
I don't agree with this statement. if you see I1 then it is I1.
How can it look like VS1 

The VS grades are the grades if examined without a loop will look
clean. SI grades are the grade where experienced eye would see the
inclusions without a loupe.

When I said “looks like VS1”, it was meant “as seen without a
loupe”.

Beside going from I1 to VS1 was obvious exaggeration to make a point
about discrepancy of appearance and the certificate.

It is less dramatic in real life.

Leonid Surpin.


#13
are sure you about this ? perhaps my memory is not so accurate but
i think yehuda grades thier stones after they have been filled i
had one a couple of years ago that was clarity graded SI-2 and
definatly looked like SI-2 

Fracture filling not alway results in visual improvement. There could
be nasty feather visible through the crown, after treatment it looks
less nasty, but the size and location is the same, so is the grade.

You could also encounter stone which was repaired by someone who did
not know about fracture fillingand it become obvious.

From GIA standpoint, fracture filling does not influence clarity
grade, it improves appearance and makes stone easier to sell. The
certificate should state the clarity grade as it was never treated.

Leonid Surpin.


#14

some treated diamonds have no fracture filling, only laser drill
holes. these have to be disclosed also since they are also treated.


#15
but I believe the question was, if the filling has been burned out
through torch heating is there any way to prove that the stone used
to have fracture filling. 

Yes that’s what I’m looking for, a kind of post mortem.


#16

Another bit of info concerning identifying filled diamonds before
repair and possibly after repair damage has occurred: Some fractured
filled diamonds will have a laser inscribed logo on them. OVED says
that they inscribe their name on all diamonds that are a half carat
and up. So crank up that magnification and take a good look before
turning on the torch. Many of these fillers are also damaged by acids
as well as heat.

Carrie
www.carrienunes.com


#17

As for proving the diamond was fracture filled after the filler has
already been damaged, I guess the only way is if there is some
filler residue left that can be observed. In many cases, damaged
filler can be cleaned out and replaced by one of the companies that
produces these treated diamonds. Best of course to discover the
filler before repair work begins and discuss all observation with
the client beforehand. And it is true that many customers may not be
aware that they are handing you a fracture filled diamond. These
have been produced since the late 1980’s, so there are lots of them
around.

Fracture filling creates what GIA calls an “apparent clarity”. The
actual clarity of the diamond is in fact lower but the filler
improves the apparent clarity.

Hope that helps-Carrie Nunes
www.carrienunes.com


#18
Yes that's what I'm looking for, a kind of post mortem. 

It is not an easy question to answer. From the point of view of
scientist in a fully equipped lab - the answer is yes.

A jeweler who inadvertently burned out the filling and been able to
prove to the customer - it would depend on jeweler equipment,
customer knowledge, jeweler knowledge, degree of damage to the
filling, and so on.

So the answer is maybe.

Leonid Surpin.


#19

I burned one once years ago when they were first becoming available,
and I’ve seen a few since that other people have burned, and
customers have been unaware of. Most of the time it happens in
retipping, and the filling doesn’t entirely burn out - it turns a
brown color. It’s pretty obvious. If you loupe it, you can usually
see bits of the flash effect still in some areas, along with the
brown.

Now, everytime I retip or solder near a large diamond, I loupe it
and turn it every which way to make sure there’s no flash (as well
as chips under a prong or dangerous inclusions). I find one every
few months that is filled.

Lauren


#20
Yes that's what I'm looking for, a kind of post mortem. 

That’s what a GG appraiser is for!

Elaine
http://www.CreativeTextureTools.com