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Fracture healing/filling of Mong Hsu ruby


F o r e i g n A f f a i r s

Fracture healing/filling of Mong Hsu ruby


Richard W. Hughes Olivier Galibert
RWH Publishing 17u19 Boulevard
4946 Clubhouse Circle Montmartre
Boulder, CO 80301-3725 USA 75002 Paris, France
Tel/Fax: 303-530-7975; Tel: 33-1-40-20-9944
E-Mail: Fax: 33-1-40-20-9955

PICTURE THIS: a well-known European dealer sells a 2.5-carat
Mong Hsu ruby to a major jeweler in Europe. This jeweler then
sells the stone to a Japanese client through their Japanese
subsidiary. The client now takes the stone to a gemological lab,
which issues a report stating that the gemAEs fractures are
filled with a foreign substance. Now the fun really starts.
Feeling cheated, the customer returns the stone and demands a
full refund. Thus begins a lawsuit which involves several firms,
spans two continents and is still snaking its way through the
court system in France.

Today, courts are increasingly being called upon to arbitrate
such disputes, largely because sellers have failed to disclose
the glass infilling/healing of fractures in Mong Hsu ruby from
Burma. The problem is a huge one, a corundum conundrum that will
only escalate until the trade begins to enforce a policy of full
disclosure of all gemstone enhancements.

The following article examines the roots of the issue.

Mong Hsu is not Mogok

In terms of quality, Mong Hsu rubies cannot compete with Mogok
stones. There are two major problems. The first is a strong
purplish color, making most stones look like poor rhodolite
garnet. Ordinary heat treatment eliminates the purplish tint, and
the market generally accepts such heated stones without a

This is not the case for the second problem. Most Mong Hsu stones
are heavily fractured and Thai burners have combated the cracking
by filling the cracks with glass. Heating the stones with borax
and other chemicals actually melts their surfaces, including the
surfaces of cracks. This molten material then solidifies into a
glass, filling and healing the fractures shut. In the broadest
sense, this is akin to the oiling of emeralduboth treatments
involve filling fractures with a transparent, colorless
substance. Similar to placing an ice cube in water, a filled
fracture is much less visible because the filler replaces air (RI
= 1.00) with a substance which has an RI that more closely
matches the gem itself (1.76u1.77).

However, the glass infilling of Mong Hsu rubies differs in two
important respects:

  1. The Mong Hsu ruby treatment is permanentuunlike the oil in an
    oiled emerald, the glass will not drain out in the future.

  2. The Mong Hsu ruby treatment actually improves a stoneAEs
    durability, since the fractures are bonded together with glass.

Hence we have a superior treatment for Mong Hsu ruby, one which
is actually more stable than ordinary oiling. So what is all the
fuss about? First, purchasers of ruby are not accustomed to
buying heavily-fractured stones. Unlike emerald, clean rubies do
exist. Second, the glass infilling can impact the weight of the

But the biggest problem was something quite simpleuwhen Thai
burners starting glass infilling, they did not tell their
customers. Customers believed they were buying stones for which
only ordinary heat had been applied. When they learned
otherwise, they rejected the goods. To most dealers and
jewelers, fracture filling/healing with a foreign substance such
as glass represents open-heart surgery, not just a haircut.
Whether we like it or not, many dealers, jewelers and retail
buyers of precious stones do not want to buy stones which have
been radically altered in such a way. The idea of fracture
filling/healing with glass turns them off.

Unfortunately, monkeying with stones and not telling the buyer
has been business-as-usual in Thailand for years. It started
with ordinary heating of corundums (mid-1970s), passed on to
glass-filling of surface pits in ruby (1984), surface diffusion
of blue sapphire (1988) and now glass fracture-healing/filling

Market acceptance of ordinary heating was de facto; with no gem
lab in Bangkok in the mid-1970s to warn them, when foreign
buyers found out about this difficult-to-identify enhancement,
they had an inventory full of heated gems. This was not the case
with the other enhancements. A gem-testing lab was founded in
Bangkok in 1978. When the glass pit-filling and surface
diffusion first appeared in Thailand, they were quickly
recognized by local gemologists and rejected by the market as a

But the fracture-healing/filling of Mong Hsu rubies was
initially passed over by local gemologists, in part because it
is difficult to detect and in part because, frankly, certain
Bangkok gemologists became overly influenced by traders. Even
when they did detect the enhancement, they downplayed its
significance, going so far as to declare that it would not be
mentioned on identification reports if it wasnAEt visible under
greater than 10Y magnification. [ * We refuse to even comment
on that silliness.] Foreign gemologists and dealers were not so
kind. Many rejected such filled goods outright, particularly in
the important Japanese market.

This has created a very real problem, where the enhancement is
generally accepted by Bangkok dealers/gemologists, but rejected
by those outside the country. The result is that goods are
returned amidst much name-calling and hand-wringing, a situation
from which only lawyers will benefit. Compounding the problem is
the fact that laboratories around the world do not have uniform
methods of describing or dealing with this enhancement. Some
cannot even properly identify it or distinguish between
naturally-occurring inclusions and the glass infilling.

Desperately seeking solutions

So, what to do? First, gem trade must get together on this
question and decide on a solution to the mess. TodayAEs world is
one market, not one-hundred markets. This global trade makes it
important that the solutions to this problem be a global one, not

For starters, ThailandAEs gem traders and treaters need to
acknowledge that a mistake was made in not declaring this
treatment from the outset. In the strictest sense, the problem is
one of the Thai gem tradeAEs own making. Had they been honest in
properly labeling their goods from the start, they would not find
themselves in this position.

On the other hand, foreign buyers need to acknowledge that some
sort of enhancement is needed for Mong Hsu ruby. As anyone who as
ever viewed the untreated stone can testify, the Mong Hsu ruby is
not a viable gem without enhancement. The enhancement results in
a material which is both beautiful and stable. There is certainly
nothing wrong with that, so long as it is properly described.

Overall, we all must stop kidding ourselves. We must realize
that, in the eyes of the retail gem customer, the
high-temperature heating and glass impregnation of a ruby is not
the same as simply cutting and polishing it. No amount of
explaining will make it so. A gem which only requires polishing
to reveal its beauty is far rarer than something which needs both
polishing and ordinary heating. And that is rarer than something
like the Mong Hsu ruby, which needs polishing, high-temperature
heating, fracture healing and glass impregnation. The market
should reflect these realities in its descriptions of goods and,
most importantly, in its pricing. Remember, gems and jewelry are
luxuries. They compete against a number of different goods and
services. If we donAEt start getting our act together, that retail
customer will stop buying more than just rubies.


Solutions rarely come easily. But the first step to solving any
problem is to discuss it. The authors believe it is far better to
discuss problems without solving them that to solve problems
without discussion. We are interested in the views and ideas of
others. Feel free to contact us.

Richard W. Hughes Olivier Galibert
RWH Publishing 17u19 Boulevard
4946 Clubhouse Circle Montmartre
Boulder, CO 80301-3725 USA 75002 Paris, France
Tel/Fax: 303-530-7975; Tel: 33-1-40-20-9944
E-Mail: Fax: 33-1-40-20-9955


I have a couple of problems with the idea of fracture filling

First off, you say this treatment is permanent? What happens
when the uneducated jeweler decides to retip a prong on one of
these stones? What about pickling solution, ultrasonic and steam

I know a few jewelers that had nightmares over ruining fracture
filled diamonds when they first appeared on the market.

I believe the only reason the fracture filled process came about
was for DECEPTION. And only after it was discovered, these people
that were doing it fessed up to the fact and claimed to be doing
a “service” to the industry! Give me a break! Greed would be a
better word for it.

I have tried to educate myself on how to detect treatments and
will only buy goods from a dealer who totally understands my
feelings about this. Its unfortunate that our industry has come
to this point and I will not buy any stone that has been fracture
filled. I believe there is a place for good quality stones and
poor quality stones, and for the customer that cant afford
either, synthetics should be the alternative. I wonder how many
times when buying a parcel of small colored stones, one ends up
getting a “mixture” of natural and treated stones without being
aware of it? There may be a place for fracture filled stones, but
until the process is truly permanent AND undectectable, they wont
be in my store.



Ken you are sooooooo right… I have been one of those
unfortunate jewelers… DeDe

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