How can you tell if an emerald is treated?

[Kim Bruun]

I have read that virtually all emerald available today it treated with resins or oils to fill out the cracks. Is emerald, by nature, a poor quality stone that needs more help than just cutting to become beautiful? Are the treatments visible if you know what to look for?

I have a Colombian .57 light green, fairly clear emerald, and every time I come across one of these articles, I worry about it.

I've never had a problem with heat treated stones - after all, where would tanzanites and paraibas be without it? And with that in mind, I would be a hypocrite to turn down a gorgeous ruby just because it was heated to remove an ugly brownish tone. But actually introducing something into the stone, like an oil or a resin, that is kinda like flux healing for me. It just strikes me as invasive.

 

[serenitydiamonds]

Date: 1/7/2010 7:39:22 AM
Author:Kim Bruun
I have read that virtually all emerald available today it treated with resins or oils to fill out the cracks. Is emerald, by nature, a poor quality stone that needs more help than just cutting to become beautiful? Are the treatments visible if you know what to look for?


I have a Colombian .57 light green, fairly clear emerald, and every time I come across one of these articles, I worry about it.


I''ve never had a problem with heat treated stones - after all, where would tanzanites and paraibas be without it? And with that in mind, I would be a hypocrite to turn down a gorgeous ruby just because it was heated to remove an ugly brownish tone. But actually introducing something into the stone, like an oil or a resin, that is kinda like flux healing for me. It just strikes me as invasive.

Treatments are visible through a loupe if you know what you are looking for. For a rough idea, you look at the face of each facet in reflected light, looking for cracks and features in the surface. Emerald treatments only affect the surface of the stone, so that is why you examine the surface. This is only a basic test and it is not complete, but it will give you a rough idea on whether something has a lot of treatment or not. A lot of treatment would be a surface reaching inclusion(s) that cross several facets. A lightly treated stone would have very few surface reaching inclusions that are very small. This is a very subjective based analysis, even at the labs.

Emeralds have been treated with oils for hundreds of years, and for resins for a very long time also. That''s just the nature of that particular gemstone. The amount of oil or resin that is introduced to a high quality emerald is very very small. It''s not changing the stone in any way other than to smooth out the light reflections caused by air pockets in the surface cracks of the gem. It''s not the same as flux healing or glass filling of other gemstones, which are very invasive. The inclusions of an Emerald, jardin or garden, are what gives the emerald it''s velvety uniqueness, which exists in no other stone.

--Joshua

 

[chrono]

There are indeed clean-ish looking emeralds have absolutely no treatment (or even oil) but those are incredibly rare and I don’t even want to think of the price of such stones. Let’s just say it’s beyond the range of mere mortals like us, even the wealthy ones. I think it’s just the nature of emerald formation that makes them so prone to being included in their natural state. I would not consider them a poor quality stone because the colour is just unbelievable in fine quality emeralds. Of course, the lesser the treatment, the better.

I don’t like the idea of resin but will accept minor oiling. If I’m not mistaken, there are even different levels/degrees of oiling in emeralds. Yes, with a trained eye and good loupe, you can spot signs of resin filling and oiling. The tell tale signs are usually visible along the cracks or any inclusion.

 

[Kim Bruun]

Thanks for the info, guys! I know oil treatment and flux healing aren''t exactly the same. Will the oil or resin eventually dry out in an emerald? I have heard of stones that looked great when they were bought, only for the oil to dry out and the cracks becoming all too visible to the naked eye after a few months.

 

[serenitydiamonds]

Date: 1/7/2010 9:04:25 AM
Author: Kim Bruun
Thanks for the info, guys! I know oil treatment and flux healing aren''t exactly the same. Will the oil or resin eventually dry out in an emerald? I have heard of stones that looked great when they were bought, only for the oil to dry out and the cracks becoming all too visible to the naked eye after a few months.

Hmmm.... oil can dry out but usually takes years (sometimes decades), not months, it all depends on the quality (i.e. price) of the emerald bought though. They can be re-oiled quite easily though.

--Joshu

 

[chrono]

You will need to re-oil the emerald after a few years. Maybe 5 years or so? I guess it also depends on how heavily it is oiled, the usage of the stone and etc. As for resin, some resins will turn whitish when it dries but I’ve heard of a newer one where it doesn’t do this.

 

[T L]

I have a Columbian emarald I bought around 11 years ago (before I heard of resin filling) that is resin filled. Most of the stone is very clean, and a deep velvety green color, but there is one whitish splotch in it that the gemologist told me was caused by resin. I really wonder how many cracks it truly has. I''ve had it for years, but the emerald doesn''t seem to have had it''s resin dry out since I would imagine it would be more cloudy. Who knows, but I did buy this emerald before some of the newer and later resin treatments that are more stable.

BTW, NEVER EVER put an emerald in an ultrasonic cleaner. It will remove the oil and if there''s resin, it will show more cracks. You could damage the emerald.

 

[serenitydiamonds]

Perhaps maybe the stone just needed to be wiped clean with warm water and a brush if it discolored so quickly. An older synthetic resin from the 80's in Brazil may turn yellowish after years(Opticon). Palm Resins will turn white after awhile, but they are not considered acceptable treatment for emeralds. The newer resins, such as Permasafe and ExCel, are colorless for a very,very long time and are actually safe for ultrasonic cleaning, not that I'd ever recommend putting an emerald in one..... no matter how safe they say
--Joshua

 

[serenitydiamonds]

Date: 1/7/2010 9:21:30 AM
Author: tourmaline_lover
I have a Columbian emarald I bought around 11 years ago (before I heard of resin filling) that is resin filled. Most of the stone is very clean, and a deep velvety green color, but there is one whitish splotch in it that the gemologist told me was caused by resin. I really wonder how many cracks it truly has. I've had it for years, but the emerald doesn't seem to have had it's resin dry out since I would imagine it would be more cloudy. Who knows, but I did buy this emerald before some of the newer and later resin treatments that are more stable.


BTW, NEVER EVER put an emerald in an ultrasonic cleaner. It will remove the oil and if there's resin, it will show more cracks. You could damage the emerald.

You should take it in and have the treatment removed then get it oiled

--J

 

[T L]

Who does this?

 

[serenitydiamonds]

Date: 1/7/2010 9:35:25 AM
Author: tourmaline_lover
Who does this?

Most Emerald Dealers should be able to do that for you. Of course it depends on the resin and amount of treatment, but most resins are very easy to remove.

--Joshua

 

[T L]

I do not know of any emerald dealers in my area (Chicagoland area). Any recommendations?

 

[serenitydiamonds]

Date: 1/7/2010 9:43:35 AM
Author: tourmaline_lover
I do not know of any emerald dealers in my area (Chicagoland area). Any recommendations?

Let me research and see if there are any out there, I don''t know any offhand either.

--Joshua

 

[T L]

Thanks!! I appreciate it. It would probably be worth retreating since it's supposedly Muzo and a very deep rich velvety green. I love the color better than my tsavorites. It just doesn't sparkle as much.

 

[serenitydiamonds]

Date: 1/7/2010 9:46:27 AM
Author: tourmaline_lover
Thanks!! I appreciate it. It would probably be worth retreating since it''s supposedly Muzo and a very deep rich velvety green. I love the color better than my tsavorites. It just doesn''t sparkle as much.

Cannot seem to find anyone in the Chicago area, did you get your Emerald in Chicago? I L O V E emeralds, so naturally Tsav will always be second in my mind... I know many others feel differently. Do you have a pick of your gem?

--Joshua

 

[T L]

Date: 1/7/2010 7:54:20 PM
Author: serenitydiamonds

Date: 1/7/2010 9:46:27 AM
Author: tourmaline_lover
Thanks!! I appreciate it. It would probably be worth retreating since it''s supposedly Muzo and a very deep rich velvety green. I love the color better than my tsavorites. It just doesn''t sparkle as much.

Cannot seem to find anyone in the Chicago area, did you get your Emerald in Chicago? I L O V E emeralds, so naturally Tsav will always be second in my mind... I know many others feel differently. Do you have a pick of your gem?

--Joshua

Thanks Joshua for checking. I did not get it in Chicago. Here''s an incredibly bad picture, but it''s a rich deep bluish green with a velvety appearance.

 

[T L]

Here''s a better picture, that a piece of dirt on top of the stone. Green just doesn''t photograph well with my camera. It is very saturated.

 

[T L]

Joshua,
Do you know if I can send it out to someone to do this retrreatment, and if so, who? Thanks in advance.

 

[serenitydiamonds]

Very nice, I can imagine how it looks. Emeralds are almost impossible to photograph.

--Joshua

 

[serenitydiamonds]

Date: 1/7/2010 9:50:55 PM
Author: tourmaline_lover
Joshua,

Do you know if I can send it out to someone to do this retrreatment, and if so, who? Thanks in advance.

I would think any of the Pricescope emerald vendors should be able to help you. I can also.

--Joshua

 

[chrono]

Date: 1/7/2010 11:20:16 PM
Author: serenitydiamonds
I would think any of the Pricescope emerald vendors should be able to help you. I can also.

--Joshua

Since PS isn’t a selling/buying site, there aren’t any PS vendors per se. There are vendors that Pricescopers might like and often recommend but I don’t know of any that specializes in emeralds and emerald treatment. Josh, do you just sell emeralds or do you also do re-oiling as well?

 

[serenitydiamonds]

Date: 1/8/2010 9:00:18 AM
Author: Chrono

Date: 1/7/2010 11:20:16 PM

Author: serenitydiamonds

I would think any of the Pricescope emerald vendors should be able to help you. I can also.


--Joshua

Since PS isn’t a selling/buying site, there aren’t any PS vendors per se. There are vendors that Pricescopers might like and often recommend but I don’t know of any that specializes in emeralds and emerald treatment. Josh, do you just sell emeralds or do you also do re-oiling as well?

Oh I would guess that most of the emerald sites referred to here like Embassy Emeralds would be able to, etc. Yes I have the ability to have Emeralds re-oiled or re-treated as well. The ExCel treatment lab is also in NYC, so that is also available.

--Joshua

 

[T L]

THank you Joshua for the information. Are all resin filled emeralds able to be treated to remove the resin and be replaced with oil, or are some just too heavily treated. What are the criteria for a good retreatment candidate as far as a resin filled emerald is concerned?

 

[serenitydiamonds]

Date: 1/8/2010 3:59:48 PM
Author: tourmaline_lover
THank you Joshua for the information. Are all resin filled emeralds able to be treated to remove the resin and be replaced with oil, or are some just too heavily treated. What are the criteria for a good retreatment candidate as far as a resin filled emerald is concerned?

No problem!

Naturally, every stone is different, but typically most of the good quality stones can have resin removed safely. Remember, most treatment just fills the cracks and fractures on the surface, so it would only affect inclusions that reach the surface of the emerald. It's not like a filled diamond where they drill into the actual stone and fill.

I would say moderate (or medium) enhancement or better is a very safe bet for removing resin. That covers about 80-90% of what is out there in the good quality range. If it's a fairly clear stone and not pieces glued together (rare and obvious) you're usually ok. If the stone isn't transparent because of the number of inclusions, re-treatment is not a good idea. Of course, each stone has to be checked and examined up close before anything for sure could be said.

I also don't think resins are particularly bad either, if they are modern (last ten years or so). GIA did some serious testing on modern synthetic resins (ie. Permasafe and ExCel) and they had excellent durability and very long life spans. They are signifcantly more stable than Cedar oil which is the traditional method of enhancement.

--Joshua

 

[T L]

Date: 1/8/2010 6:30:28 PM
Author: serenitydiamonds

Date: 1/8/2010 3:59:48 PM
Author: tourmaline_lover
THank you Joshua for the information. Are all resin filled emeralds able to be treated to remove the resin and be replaced with oil, or are some just too heavily treated. What are the criteria for a good retreatment candidate as far as a resin filled emerald is concerned?

No problem!

Naturally, every stone is different, but typically most of the good quality stones can have resin removed safely. Remember, most treatment just fills the cracks and fractures on the surface, so it would only affect inclusions that reach the surface of the emerald. It''s not like a filled diamond where they drill into the actual stone and fill.

I would say moderate (or medium) enhancement or better is a very safe bet for removing resin. That covers about 80-90% of what is out there in the good quality range. If it''s a fairly clear stone and not pieces glued together (rare and obvious) you''re usually ok. If the stone isn''t transparent because of the number of inclusions, re-treatment is not a good idea. Of course, each stone has to be checked and examined up close before anything for sure could be said.

I also don''t think resins are particularly bad either, if they are modern (last ten years or so). GIA did some serious testing on modern synthetic resins (ie. Permasafe and ExCel) and they had excellent durability and very long life spans. They are signifcantly more stable than Cedar oil which is the traditional method of enhancement.

--Joshua

So unlike a lead glass filled ruby, which is like 90% glass, a resin filled emerald is still mostly emerald?

 

[serenitydiamonds]

Date: 1/8/2010 8:48:50 PM
Author: tourmaline_lover

Date: 1/8/2010 6:30:28 PM

Author: serenitydiamonds

Date: 1/8/2010 3:59:48 PM

Author: tourmaline_lover

THank you Joshua for the information. Are all resin filled emeralds able to be treated to remove the resin and be replaced with oil, or are some just too heavily treated. What are the criteria for a good retreatment candidate as far as a resin filled emerald is concerned?

No problem!


Naturally, every stone is different, but typically most of the good quality stones can have resin removed safely. Remember, most treatment just fills the cracks and fractures on the surface, so it would only affect inclusions that reach the surface of the emerald. It's not like a filled diamond where they drill into the actual stone and fill.


I would say moderate (or medium) enhancement or better is a very safe bet for removing resin. That covers about 80-90% of what is out there in the good quality range. If it's a fairly clear stone and not pieces glued together (rare and obvious) you're usually ok. If the stone isn't transparent because of the number of inclusions, re-treatment is not a good idea. Of course, each stone has to be checked and examined up close before anything for sure could be said.


I also don't think resins are particularly bad either, if they are modern (last ten years or so). GIA did some serious testing on modern synthetic resins (ie. Permasafe and ExCel) and they had excellent durability and very long life spans. They are signifcantly more stable than Cedar oil which is the traditional method of enhancement.


--Joshua

So unlike a lead glass filled ruby, which is like 90% glass, a resin filled emerald is still mostly emerald?

For a good quality emerald, there is so little filling (resin or oil), if you remove it the weight of the stone will not change. For a high quality emerald (faint enhancement or better), you would have to struggle to find the surface inclusion. With emeralds, as with most gemstones, you get what you pay for. So the best way to avoid poor stones is to buy from trusted vendors and not think you are going to buy a 1 carat high quality emerald for under $400. Here are some links to show you what types of emeralds to avoid:

Too Included

Uneven color, looks died

The inclusions of an emerald tell a story. Minor inclusions with very few touching the surface of the stone will give you a beautiful stone with moderate (medium) or less treatment that is 99.99% emerald. Heavily included stones that are not transparent, have many fractures touching the surface, will give you an un-durable stone that could have significant amounts of treatment. An emerald will always tell you their story when you look at it closely.

--Joshua

 

[Tacori E-ring]

How interesting. My dad buys my mom emeralds when he travels to Colombia and I know she has never had them oiled. Some of them are probably 20+ years old. Is there anywhere in NC that does this? TIA!

 

[Sagebrush]

All,

As part of the certification process, AGL will have the oil removed and certify the stone once completed. I have had this done several times. There is a difference between an untreated stone and a flawless stone and you may have a very nasty surprise once you see the difference in the look of the stone once the filler is removed.

With very high end emerald, it will be done because the price difference between a very fine emerald graded "minor" (normally the lowest grade though some labs use "insignificant") and one graded "none" can be quite significant.

Bear in mind, labs can disagree. I conducted an experiment at the behest of several Colombian dealers. Four emeralds were cut and boiled out in my presence. I submitted them to all the major labs with inconsistent results. One stone was graded "moderate", "minor" and "none." and the difference in price is not moderate.

Best,

 

[serenitydiamonds]

Date: 1/9/2010 4:08:51 PM
Author: Richard W. Wise
All,


As part of the certification process, AGL will have the oil removed and certify the stone once completed. I have had this done several times. There is a difference between an untreated stone and a flawless stone and you may have a very nasty surprise once you see the difference in the look of the stone once the filler is removed.


With very high end emerald, it will be done because the price difference between a very fine emerald graded ''minor'' (normally the lowest grade though some labs use ''insignificant'') and one graded ''none'' can be quite significant.


Bear in mind, labs can disagree. I conducted an experiment at the behest of several Colombian dealers. Four emeralds were cut and boiled out in my presence. I submitted them to all the major labs with inconsistent results. One stone was graded ''moderate'', ''minor'' and ''none.'' and the difference in price is not moderate.


Best,

Apologies on my late reply I wanted to make sure I had researched this properly. AGL does not remove treatment of emeralds during the certification process. I hadn''t heard of this in all the times I take mine in so I had to check with them directly a couple times to verify this. Apparently this was or might have been a service they offered in the past. Currently, when submitted for laboratory grading they examine the stone with it''s treatment in place, and also determine the type and amount of treatment used. If the client wishes to have the treatment removed prior to grading, they will refer you to a vendor or the steps necessary for treatment removal. Most lightly treated stones are very easy to clean. Low quality stones are very difficult to remove treatment from.

You are correct, the treatment analysis (as is anything from a lab for ANY gemstone) can and will vary as it is subjective. Although, AGL and the major labs claim this variation is no where near as significant as before they standardized. The price difference between certain grades can definitely be tremendous.

We were not discussing the complete removal of emerald treatment as that could definitely make them less attractive. We were discussing the removal and reapplication of emerald treatment for several reasons: improving aged appearance, removing treatments the client may find undesirable with oil or a preferred treatment. Most people aren''t aware that if they don''t like their treatment it can be reapplied in whatever form they do prefer. Naturally this is with nice quality stones only.

--Joshua

 

[T L]

Joshua,
When you do clean out the emerald, is there ever trace residue of the filling left?