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Cracks filled diamonds


#1

How do you check for diamonds which have cracks filled?
Supposedly even the best of the inclusion repairs turns dark over
a temperature of 1000 degrees. geo.


#2

George: The best and to my knowledge, the only way to detect
"clarity enhanced" dias. is with magnafaction. On larger stones
especially, you should see a distinct purplish “flash” when the
stone is rotated. As for the life of the treatmant, I know that
Yahoda warrents their treatment forever, even if damaged by heat
or acids.

Hope this helps;
Steve Klepinger


#3

Let me clarify this: this is a serious question, not a one liner
joke. Needed is a way of finding out a diamond is crack filled
BEFORE it is heated via prong retipping or other soldering
operation. In the promo videos there is discussion of a “rainbow
flash” at certain angles from the rear of the stone when in
strong light, but how otherwise canyou tell?


#4

Most fracture filled diamonds reveal a distinctive color flash
when the filler is viewed at different angles. GIA offers
seminars on this very subject and some of the past Gems and
Gemology magazines have some intensive articles on it. While the
flash is often distinctive it is not always easy to find. You
should study up on this as there is a lot of this material coming
on the market now.


#5

Forgive me for harping on this subject, but I fear that someone
will take all the “go ahead and heat the diamond it will never
hurt it” advice to heart and never know about crack filled ones
until they end up paying for a damaged diamond with a big ugly
discoloration in the middle. Here are a couple of URLs describing
the stones. The trouble witht hem is the second or third owner
might not know they are crack filled. And using the advertised
method of looking for the color flash is useless if they are
deeply set: http://www.goodoldgold.com/clarity2.htm
http://www.yehuda.com/


#6

How do you check for diamonds which have cracks filled?
Supposedly even the best of the inclusion repairs turns dark over
a temperature of 1000 degrees. geo.

Look for a purple “flash” within the stone. It would probably be
a lot easier if you had a sample to study first. The material
that fills the inclusions is purple and at the right angle is
visible. Unfortunately, The “right angle” never seems to be face
up. Six months or so ago I was fooled by one. So was the diamond
dealer. Take your time.

Bruce D. Holmgrain Maryland’s first JA certified Master Bench
Jeweler http://www.goldwerx.com
manmountaindense@goldwerx.com


#7
using the advertised method of looking for the color flash is
useless if they are deeply set 

This can be very troublesome. This is why one should use
fiberoptics under high magnification to not only look for flash
effect, but also "ice-in-water"look and bubbles. This takes
practice and as one has suggested, you need to have a sample so
you can learn to compare. A loupe will not see this at
all–only the obvious flash (about 65% of stones).


#8
   How do you check for diamonds which have cracks filled?
Supposedly even the best of the inclusion repairs turns dark
over a temperature of 1000 degrees. 

Some of the earlier treatment turned dark with long term
exposure to UV (daylight). Supposedly that manufacturer has
corrected that problem. All of the materials used have melting
points of less than 600 degrees–therefore torches will
definitely cook the material out. They are all a form of
high-lead content glass.

High power mangification and use of a fiberoptic light source is
the best method to detect filled diamonds. When you are looking
at a stone, remember that the inclusion has been made less
visible–kind of an ice-in-water appearance, not the typical
look of most inclusions. For this reason, a small inclusion
that is filled (orginally of VS nature) will be difficult to
spot without having used a fiberoptic light source which makes
fainter inclusions stand out. When viewing a suspected
inclusion and looking for the flash effect, look nearly parallel
to the plane of the inclusion while moving the light source
around (fiberoptic). That is how to best find a flash effect
which can be seen as faint yellowish green, violet, purple,
yellow, orange or orangish red (depending upon the treater and
type of glass used. If you see the nearly full or full rainbow
while looking at an inclusion perpendicularly, that is not flash
effect, but natural irridescence which occurs in some
inclusions. A second indicator is that where the inclusion
breaks the surface, a whitish line is evident (a breakdown in
the glass). This is not always obvious, but is rare in
untreated inclusions. A third indicator is that the inclusion
has bubbles in it–typical for molten glass–and it will be rare
to see that look in an untreated diamond. I taught the lab
(hands-on) for the AGS conclave for three years and this last
year taught a class at the AGTA in Tucson on identification of
fracture filled diamonds.