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Oiling an emerald properly


#1

I have a customer that says they need there big emerald that is in a
ring oiled. I’ve been in this business for a long time but I’m not
sure how to do this properly.


#2

Larvick- I have oiled many emeralds. I use cedar oil and place the
stone under a warm lamp over night. Some times if I’m feeling brave,
I’ll put the stone in oil and into my vacuum chamber for a few
seconds for full penetration. Be sure to wipe any residue off of the
surface of the stone. Especially if it contacts the skin as cedar oil
can irritate skin. It really improves an emerald and is kosher if you
disclose the treatment.

Jo
www.timothywgreen.com


#3

My name is Lee Horowitz, a Gemologist and I can assure you, you will
not be able to oil the emrald yourself probabaly. The oil is pumped
into an emearld to hide the cracks in it and also to darken Columbia
emeralds. In India they also add dye to the oil to also improve color
to the meradl as well if very very light lamost green beryl color.
The oil is then sealed into the stone with an opticon a glue like
resin that then seals the pores of the stone. When that sealing comes
off through wear and tear the oil then comes out of the stone over
years.

The oiling is done via a vacum pump. You may want to consult a friend
of mine a gemologist and rough anbd cut stone appariaser and dealer
and he may refer you to someone who does oiling.

Lee Horowitz, Gemologist
Peru Blue Opal Ltd
Horowitz Co-KCIG Co Ltd


#4

This is going to sound bizzare and there may be a few snickers from
some folk who think they are absoloute authorities on the subject.
put the emerald in your home freezer for a an hour or so then take
it out and drop it into room temp oil. i dont know the science of how
it works but it does, it is the method my stone cutter friend uses

best regards
goo


#5
This is going to sound bizzare and there may be a few snickers
from some folk who think they are absoloute authorities on the
subject. put the emerald in your home freezer for a an hour or so
then take it out and drop it into room temp oil. i dont know the
science of how it works but it does, it is the method my stone
cutter friend uses 

At a guess, shrinkage from cooling might cause cracks and fissures
to close up a little. Then dropping it into room temp oil warms the
stone, and the fissers open up a little again, sucking in the oil.
Not as effective as drawing a full vacuum on the stone and, still in
the vacuum, then dropping it into oil, but it might still be good
enough to make enough of an improvement many times, and it’s a lot
easier than vacuum pump setups to do this. The best results I ever
got were first warming the stone, setting it under a bell jar in the
vac pump so it was balanced on a small support over the container of
also warm oil. Pull a full vacuum on the whole setup, then jiggle the
vacuum table so the stone falls into the oil, still under vacuum (no
air in the cracks.) Return to normal pressure and put in a warm, not
hot, toaster oven for an hour.

Even better results, though I’ve never tried it, would be to then
autoclave it. That’s putting it into a pressure chamber. So you’d
first pull any air out of any fissures, then put it in oil, and then
pressurize it. That would force oil in better and farther even than
plain air pressure can do.

And at that point one might also discuss the whole ethics of oiling
the emeralds in the first place. Yes, everyone does it. But does that
make it right and ethical. Another topic for discussion.

Peter


#6

The purpose of oiling an Emerald is to fill the inclusions with an
oil of the same refractive index as the emerald. When this is done,
the inclusion will not show. If the index of refraction of the oil
is different than the index of refraction of the Emerald, all you
have is an oily emerald…

Index of Refraction constants can be found on the Web:
http://www.3dlapidary.com/HTML/Materials3.htm

Emerald 1.560 - 1.605

You can buy an oil with that specific index of refraction:

http://www.2spi.com/catalog/ltmic/cargille-standard.shtml

Or you can use some standard oils, which come close.

Oil, Clove 1.535
Oil of Wintergreen 1.536

The emerald is put in the oil, and a vacuum pulled to remove the air
from the inclusion. When the pressure is released, the oil fills the
inclusion, and the inclusion will not show.

Opticon is one of the fillers sometimes used, and it is not normally
hardened afterwards. At least I have never used the hardner. It
makes the process non-reverseable. Its refractive Index is 1.54.
http://www.ruby-sapphire.com/cloak-dagger-opticon.htm

One of the negatives of using Opticon, is that it boils before the
lower vacuum pressures are reached. So, it looks like air is coming
out of the stone, but it is actually the Opticon boiling off.

You can see the Vacuum Process at my Web Page. This was a very large
Emerald Rough, about the size of your fist.

http://www.rocksmyth.com/treating/treating.htm

Love and God Bless
randy
http://www.rocksmyth.com


#7

After my recent gaffe on blue garnets, I figured I’d better catch up
on my Gems and Gemology reading. It seems that I haven’t managed to
finish an issue in two years. However in my attempt to catch up on
my reading, I came across an article in the Summer 2007 issue on the
durability of emerald treatments. It seems pretty clear that the
surface hardened fillers (Norland Optical Adhesive 65 and
Surface-hardened Opticon) were far more stable and durable than any
of the other fillers they studied. This is something to think about
if you’re just going to try to throw some cedarwood oil back into a
stone. Incidentally, they tested them with a chill-thaw cycle as
part of the test and some of the emeralds themselves (not just the
fillers) were damaged during these tests, so I’m not sure that you
would want to go ahead and throw a few in the freezer.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
www.spirerjewelers.com


#8
The emerald is put in the oil, and a vacuum pulled to remove the
air from the inclusion. When the pressure is released, the oil
fills the inclusion, and the inclusion will not show. 

I’m not sure I’d try this with an emerald of any value, but you may
already have equipment to create a vacuum for filling an emerald’s
inclusion with oil. Food vacuum sealers (Foodsaver is one brand) do a
great job of forcing a marinade into raw meat in a very short period
of time by pulling a vacuum in a jar (using one of their special
lids). I haven’t tried it with an emerald, just a thought.

Jamie


#9

daniel, it would be facinating to read this article that describes
the freeze / thaw cycle tests you describe in this thread. the man
who introduced me to the freezer method for oiling emeralds also has
the authority to place GG. after his name. could you please provide
a link or source so that i may be enlightened and not pass along
erroneous method,

best regards goo


#10

According to my imagination, emeralds can be oiled by the following
steps:

  1. firstly we should clean the emeralds with acid so that its pores
    can get freed from other dust and impurities.

  2. After getting the emeralds cleaned with acid,we should further
    let the emeralds get dry under a lamp or natural sunlight

  3. and finally we should leave the emeralds which are to be oiled in
    a small dish having oil in it.

  4. Leave the emerald for atleast 48 hours and then wipe it with a
    clean cotton cloth.hence the inclusions are less vissible.

Its just my imagination. Needs to try this out.


#11
it would be fascinating to read this article that describes the
freeze / thaw cycle tests you describe in this thread. the man who
introduced me to the freezer method for oiling emeralds also has
the authority to place GG. after his name. 

I am not Daniel, however I also can use G.G. after my name. Emeralds
can have 3 phase inclusions, this means a solid, a gas, and liqu= id.
If the liquid freezes, it expands. Emeralds are known to have
inclusions an= d fractures, and I would not like to test an emerald by
freezing it. Certainly not= conditions an emerald would experience
from being dug out of the ground, cut, and polished.

Richard Hart


#12

I have a couple degrees in geology and mineralogy…whoopee.

I think I learned more about minerals and crystals in one semester
of mineralogy than a GG learns in the whole course. I don’t recall
anything in GIA’s literature that discusses tektosilicates or Miller
indices, for example, and a basic understanding of such things really
is necessary before much useful learning can take place concerning
our little gemstone friends.

I don’t mean to slam anyone, but GIA’s intention with the GG courses
is to train jewelers and others who do not have a scientific
background, as much as can be done, given that shortcoming. It should
be considered an introduction to mineralogy, at best. I know of
nothing in GIA’s courses that would lead anyone to think freezing an
emerald might be a reasonable part of the “oiling” process.

I’ve been cutting stones for almost four decades, and the idea of
freezing an emerald, especially a client’s emerald, makes me cringe.
The very last thing you EVER want to do with a crystal that may
contain fissures, dislocations and two or three phase inclusions is
to heat it or freeze it. Little is accomplished by freezing except to
risk loss of the stone.

There are many ways to simply “oil” an emerald, from using a simple
penetrating oil like WD-40 (works great, by the way) at a 10 hour
room temperature soak, to using a vacuum chamber to help capillary
action pull a more viscous oil into the emerald while air is
evacuated from the fissures.

All oiling is transient, but some is more persistent than others,
and most oils will accept a vegetable or aniline dye.

If one is interested in a more permanent and difficult-to-detect
solution, there are a couple of proprietary methods available. Usual
cost is around $100/c, your risk. Very, very durable. There’s
usually an ad for this in Colored Stone magazine, I think.

There is a ton of available in the literature. Gems &
Gemology did a very good article on this subject a few years ago,
I’m sure back issues are available. Any number of books discuss the
process in depth for the person who is not too lazy to search them
out. John Sinkankas’s “Emerald and Other Beryls” is a great place to
start, as well. That work is a little dated, technologically
speaking, but simple oiling is pretty low tech.

All treatments require disclosure, of course.

Wayne


#13

If the liquid freezes, it expands

Only if it’s water. Water is an exception to the rule. All other
liquids (I think water is the only exception) contract when they are
frozen. I tried to look up emerald’s three phase inclusions to find
out what the liquid consists of but none of the sites I read gave it
a name other than “liquid”. Is it water? If that’s the case then, yes
it would be a bit dodgy to put them in the freezer. If it’s any
other liquid then it should be okay in theory. Hopefully one of the
site’s GG’s can expand (no pun intended) on this.

Helen
UK


#14

Goo,

The article was in Gems and Gemology, the quarterly magazine put out
by the GIA. You might be able to access it through their archives. It
was dated Summer 2007. There isn’t a huge amount about the
freeze/thaw cycles as it was just one of many tests they conducted.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
www.spirerjewelers.com


#15
I don't mean to slam anyone, but GIA's intention with the GG
courses is to train jewelers and others who do not have a
scientific background, as much as can be done, given that
shortcoming. It should be considered an introduction to mineralogy,
at best. 

I have to agree with that. I am a GG and I found presentation is
extremely primitive and one has to be in very generous mood to call
it an introduction to mineralogy. Another thing is GIA Gems and
Gemology publication. Total waste of paper! On their websites GIA
makes available for download old editions of Gems and Gemology. Those
are quite good. But recent ones with glossy pictures…, absolute
junk.

Leonid Surpin
www.studioarete.com


#16

Only if it’s water. Water is an exception to the rule. All other
liquids (I think water is the only exception) contract when they are
frozen.

the liquid is probably water, left over from hydrothermal deposition
of the silicates. and three substances expand when they change from
liquid to solid:

  1. water which is densest at 4 degrees C and then expands to 0 C
    where it freezes (this is why ice floats as it is less dense than
    very cold water.

  2. Antimony and bismuth, which are not really a problem as they are
    both solid at room temperature, so won’t expand upon “freezing”
    (that is further cooling).

as was said above, i learned a lot in mineralogy class (geology
major); and i get a little frustrated when someone tells me that I
have the wrong name for my stone as it doesn’t look like one that
they have (no testing or analysis, it just looks different).

that’s my rant for the moment

john


#17

Leonid,

On their websites GIA makes available for download old editions of
Gems and Gemology. Those are quite good. But recent ones with
glossy pictures..., absolute junk. 

This is just hogwash. I’ve been reading the magazine for 30 years
and they are producing the exact same kind of articles now as they
were 30 years ago. If anything, they’ve gotten more technical, with
the advancement of knowledge in the field. Some might find that more
daunting (I certainly do), but the quality of writing and amount of
knowledge in each issue is still the same.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
www.spirerjewelers.com


#18
i learned a lot in mineralogy class (geology major). and i get a
little frustrated when someone tells me that I have the wrong name
for my stone as it doesn't look like one that they have (no testing
or analysis, it just looks different). 

John, what would be an example?

Richard Hart


#19
This is just hogwash. I've been reading the magazine for 30 years
and they are producing the exact same kind of articles now as they
were 30 years ago. If anything, they've gotten more technical,
with the advancement of knowledge in the field. 

It is that property, what you call “technical” that caused me to
drop the subscription. I do not shrink in presence of scientific
jargon and sometime it is the only way to address the subject, but
what they are doing is a gratuitous. The so called technical articles
are written in such a way like they are trying to hide that they have
nothing to say, so they load it with scientific jargon. The old
articles are different. The jargon was used to underline the depth of
instead of hiding the dearth of it.

The method of testing they describe is absolutely useless unless one
wants to spend untold amount of money on equipment. If I am at a show
or in a field, how it is useful? Have they ever discussed field
gemology in the past 30 year ? There were articles before. I actually
read all the editions starting with the very first one. Did they
approach the subject of separation of natural versus lab-grown
material from the “poor gemologist” point of view ? All their method
centered about super expensive equipment. I do not know about you,
but I have neither budget for such equipment, nor place to put it. So
how it is useful ?

There are methods which do not require x-ray spectrographers and the
like, but you do not find them on the pages of Gems & Gemology. All
the other stuff they write about is available from other sources, so
there is no reason to have the subscription. I see the magazine as
not
the source of but as a sophisticated marketing tool.
What they are trying to do is not to inform, but to seed a notions
that identification can only be accomplished in fancy labs thereby
driving business for their lab. I have better use of my time than to
read marketing promos.

I would like to beat up some more on GIA, but i have to go on the
business trip for a few days. We can continue when I return.

Leonid Surpin
www.studioarete.com


#20
On their websites GIA makes available for download old editions of
Gems and Gemology. Those are quite good. But recent ones with
glossy pictures..., absolute junk. This is just hogwash. I've been
reading the magazine for 30 years and they are producing the exact
same kind of articles now as they were 30 years ago. If anything,
they've gotten more technical, with the advancement of knowledge in
the field. Some might find that more daunting (I certainly do), but
the quality of writing and amount of knowledge in each issue is
still the same. 

And remember too, that G&G isn’t intended as a countertop magazine,
a consumer magazine, a student educational magazine or a hobbyist
magazine. It’s purpose is as a professional journal, keeping
professionally interested readers up to date on the current events
and developments in gemology. The assumption is made that readers are
likely already reasonably current and trained, so already familier
with the prior art and state of the field. Whether a given issue will
be a knock your socks off issue likely depends, as it does with a
daily newspaper, or with the various professional science or medical
journals, on what’s happened since the last issue that’s worthy of
reporting, as well as whether the particular authors of submitted
articles are also good writers… When you see a bunch of the more
feel good background articles covering info that’s not so new, it
often means the editors simply needed filler because not so much new
happened…

cheers
Peter