I bought a 6 carat natural ruby (faceted) here at the Tucson Gem Show
last February and even though there were some inclusions visible with
a loupe, they were minimal to the naked eye. It is really a pretty
stone. I put it away, and took it out yesterday and now you can see
tiny whitish points streaming across the inside of the stone. This
was not visible when I bought the stone. I have looked at it off and
on so, it’s not like I just didn’t notice this when I purchased the
stone. It was not visible until now.
Does anyone have any idea what this could be? It almost looks like
wax, but it is inside the stone. Could it be that it was treated
with wax and now it is becoming visible? If it is, is there anyway to
treat the stone to get rid of this and maybe stabilized the stone
with something better?
Without seeing the stone it’s always a random guess but I would lay
odds that you have dyed material and the dye is leaking out. They
wouldn’t put wax into the stone, but treating with dyes is something
that is done out there. But there is another question raised in this
post: Are you sure it’s even a ruby? 6 ct. rubies, while not
completely unheard of, are exceedingly rare. Generally speaking they
top out at about 5 ct. Even finding ones much over 3 ct. is a chore.
And this is from someone who just sold a 2 ct. natural color ruby
for about $30,000.
Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
1780 Massachusetts Ave.
Cambridge, MA 02140
Rubies and Sapphires are the most abused gemstones as far as
treatment goes. There are hundreds of ways exist to improve their
appearance. It is impossible to say anything conclusive without
examining the stone. If you know any gemologist in your area, ask him
to take a look. If not, I can take a “stub in the dark”, but that is
all it would be. However, I would need more info:
What is the actual color of the ruby? primary, secondary, and etc.
Use GIA nomenclature if you can. What kind of light do you use to
examine the ruby. If you have dichroscope, can you describe
pleochroism of the stone. Examine the stone submerged in liquid
(water would do). Do the inclusions change appearance and in what
way. Does the ruby fluoresce? What color? Do the inclusions
fluoresce? what color? Under the microscope, is any 2-phase
inclusions present? Do you observe zoning and is it contrastive ? Do
you observe a lot of disk shaped inclusions? Inclusions that you see,
are they on the level, or they are spread throughout the stone
depth-wise. Examine the stone luster. Is it uniform or is it
changing from place to place? Describe the luster.
If you provide this info, I can try to guess of what might it be,
but it will be only a guess.
positively it was treated. It could be that a resin used to fill in a
crack has absorbed moisture and turned the “glue” whitish or that -
well I could write for two hours on the processes used to make 90%
of natural rubies - like found at Tuscon, or other gem shows-
saleable, and the materials used in those processes. It is common, it
is unfortunate- particularly if you don’t have a receipt that clearly
states from the dealer that it is a natural ruby he or she sold
you-However if you used a credit card you do have recourse in
getting your money back I wouldn’t exchange it because likely it’s
going to be from the same or a similar parcel…The only other thing I
strongly recommend in going to any show is bringing a decent loupe
and a Chelsea filter,small UV battery operated light and a small jar
of refractol- a few simple things in a kit that will prevent
surprises farther on down the road. other than the obvious treatment
there could have been dye on calcium inclusions that have faded, but
that is the most remote possibility i would care to speculate…rer
I am pretty sure you and others who mentioned dye are right. That
makes a lot of sense.
This is really a gorgeous stone, even with the flaw. It is indeed a
ruby. I tested it with my Presidium. It also is 6 carats (6.489 ct to
be exact - 10.9 x 12.1mm), I weighed it on my scale (and measured it
with my calipers).
This stone is supposedly from Africa. The luster is very good and it
is red with some magenta and bluish reflections, no zoning.
I guess there is nothing I can do to fix this defect, or is there?
At any rate, I can just keep it for myself and not sell it.
I should note that I did not pay several thousand dollars for it!! I
would have LOVED to see your $30K ruby!! Wow!! Congrats on that
sale!!
Rubies are often “repaired” using glass fillers and heat. Normally,
this is a very durable treatment that will last for years, and can
be damaged only by exposure to strong acids, extreme heat, or sharp
impacts. However, the damage from these sources usually appears on
the surface of the stone, rather than the interior. I dare not
speculate on what might have caused your white inclusions to
suddenly appear. A quick visit to a competent gemologist would
probably solve your mystery for certain.
Testing a stone with only a Presidium gem tester is equivalent to
trying the guess the type of car by the sound of its engine. When
it’s a souped up V8 you might get it right but the rest of the time
it’s wrong. I have a similar piece of equipment and the thing, at
best, is barely able to test for diamonds accurately. Assuming that
it’s a ruby because the needle points in that direction is just not
accurate. Proper testing is done with refractometers, microscopes,
dichroscopes, SG liquids and if necessary a spectroscope. In today’s
marketplace with all the treatments out there even that isn’t enough
and the more sophisticated equipment of a fully equipped gem lab is
critical. And incidentally, your Presidium gem tester will NOT
distinguish between synthetic and natural ruby.
That being said, the African ruby material that is out there (which
incidentally was initially offered in this country as “red sapphire”
because the color was so different from what was considered to be
“good” ruby color—although we had a piece looked at by the GIA and
the cert came back as ruby), while often pretty, is not considered to
be a good ruby color. Invariably it has either a brown overtone, or
some other color overtones that take it out of the fine ruby
classification. Additionally I was recently shown some treated
African ruby material (and forgive me but my memory isn’t allowing me
to recall the specific treatment used–but when I see my dealer again
I’ll make an inquiry and let you know what it was) that, while quite
lovely, was treated in a non permanent fashion, which when sold
without disclosure is only going to lead to more problems in the
field.
Of course, since it sounds like there was no disclosure on your
stone at all at the time of purchase, this is another good reason to
do your shopping in Tucson at the AGTA show where the dealers are
OBLIGATED to disclose treatments at all times. (Oh and by the way the
name is Daniel, but that’s ok because about 10% of my customers call
me David too—to which I respond—and only the older, hippie
jewelers on list are going to get this—Dave’s not here man!)
Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
1780 Massachusetts Ave.
Cambridge, MA 02140
The following three paragraphs are an excerpt from an article in the
latest National Jeweler (May 1, 2008). I have a feeling what they are
describing here may be what you got in Tucson.
But there was negative reaction to lead-glass-filled rubies, which
some of the exhibitors at the Tucson shows were selling for telltale
low prices of $10 to $50 per carat for polished goods. Since hitting
the U.S. market in 2005, the stones have circulated to the point that
the American Gemological Laboratories (AGL) started calling the
stones “composite rubies” on grading reports. The treatment, which
involves heating and injecting glass into the stones, is easily
detectable by labs, but the level of lead glass used to seal major
flaws and fractures has set off alarms.
“Do you want to call it a ruby or do you want to call it ruby pieces
in glass?” asked Dr. Lore Kiefert, laboratory director of the AGTA
Gemological Testing Center, during a seminar where she displayed a
slide of a lead-glass-filled ruby, splintered by cracks after it was
exposed to heat during the resetting process. “It’s not only cavity
filling any more. It’s more than that.”
In addition to heat, the treatments are also susceptible to
solvents, including everyday household cleaners.
It’s this last statement that makes me think that this is what you
have as it’s possible that just from normal cleaning you might have
removed some of the filler and hence the whitish spots.
Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
1780 Massachusetts Ave.
Cambridge, MA 02140
A while back, I wrote in asking if anyone could help me understand
why a 6 carat ruby I had purchased at the Tucson Gem Show would show
inclusions now that I didn’t see when I purchased the stone. I think
I know why this happened, now.
I guess many of you know about this treatment of rubies, but I was
not aware of it. I didn’t realize that when rubies are heated the
fissures and other defects in the stone may actually become filled
with a type of leaded glass. This is why it is possible to buy these
large rubies, because they are not top quality but with heating the
defects may be filled with glass making the gem more stable and more
beautiful.
Here is a short except from an article on this from PJM
(Professional Jeweler Magazine) for anyone else who is not familiar
with this type of treatment:
Whether unintended or by design, one side effect of
heat-treating rubies to embellish their color is that fissures
and cavities are sometimes filled with a glass-like substance.
Corundum, the species of mineral that produces ruby, is
routinely heated at or near the source, often in antiquated
heating devices. More modern heating units reach temperatures
close to the melting point of corundum: 2050 C. Both environments
may contain borax or alumina powders, thought to even out
temperatures and prevent heat-related cracks. However, these
powders fuse at high temperatures and form a type of molten glass
that permeates surface-reaching cracks or fissures. While its
presence is minuscule in fissures, it can actually gather and add
weight in larger pits or cavities. These glass-filled areas may
be apparent under magnification because ruby and glass have
different refractive indexes and the glass may have more surface
scratches and undercutting because it's softer than ruby.
I have learned a lot from all of you. I really appreciate your
generous sharing with those of us who came to jewelry later in life
and have much to learn in this process.