Gemstone treatments: discussion and questions

[iLander]

iLander - before Topaz was regulated there was a huge batch in the US (I think in the 90s sometime) that were waaaayyyyy of the scale when tested by a Geiger counter. Consequently, huge amounts were quarantined to cool down before they could be sold and I believe that's when more stringent regulations came in. I think, if I remember correctly, it was limited to London Blue Topaz and (I think) Sky Blue Topaz. So, it might be possible that some of the material was sold beforehand.

iLander, if you're really concerned, I'd definitely take the whole lot to be tested somewhere - it would beat blindly throwing out a lot of pieces that may have sentimental value. I bought blue topaz in the 90's too, but have had no ill effects. I've never worried about it, but I guess I'd be curious to know if there was any measurable radiation.

I have called my (tiny town) fire department and they are trying to find their geiger counter. They will call me back once they find it and have replaced the batteries . . .

I used to live in a bigger town, and I own a staff badge from the Manhattan Project. I took it to the local fire department and they checked it for me. The ambient radiation of the environment had to be compensated for, but the counter said the badge was fine. What shocked me was how high the ambient radiation was . . .

 

[ruffysdad]

I don't mind treatments like heat and irradiation, especially if the price is right and the treatment is stable.

I prefer untreated stones, but some stones I will accept with treatment like minor filling on emeralds, and heated cuprian tourmalines. As always, it's personal preference, and there's absolutely nothing wrong with treated gemstones, except for the prevelance of non-disclosure. I have a big problem with that, and charging untreated prices for treated gems (hello Tiffany & Co.).

I totally agree. There are a lot of gemstones today that have been treated by heat, oiling, or irradiated and I have no problems with any of them except in the case of non-disclosure. Treatments have been around almost as long as gemstones have been mined. Ever see a piece of untreated zoisite? We're talkin' ugly with a capital UGH ! Cook that puppy right, you wind up with tanzanite and something that's worth drooling over.

The big sin in my book, is marketing a stone as natural when it's been enhanced in any way, shape or form.

Pete

 

[PrecisionGem]

I actually have a question about how a tourmaline "should" be heated...
Experts, please help me~thank you!

I have a unheated copper bearing tourmaline that has some grey in it, so I'd like to heat it myself at home...
Is it possible and how? And is it safe to do so?

I don't want to end up with a colorless stone or a cracked stone

I'll check my notes tonight, but I think I have heat the Mozambique material to 585 C which is 1085 F. Your normal oven can't go this high. I ramp up by changing the temperature 100 degrees per hour, hold the stone for 1 hour, then allow the oven to cool by it's self which is about 12 hours. The stone is packed in a crucible and investment powder. There is always the chance for the stone to crack. I have had some stones that were flawless crack, and I've had some with inclusions that didn't.

Gene - whilst you're looking at your notes, do you happen to know the temperature to heat Kunzite to please? I've got one that was once vibrant pink but is now almost colourless despite being in my safe and not exposed to sunlight ever I was very tempted to put it inside a chicken and cook in the oven but looking at your temperature guide for Tourmaline, I'm guessing that wouldn't work?

I have never heated Kunzite, so I can't help you with that one. There really isn't any published heating recipes that I am aware of. I think these are for the most part heavily guarded secrets. I know myself, Lisa and Roger have shared our experiences with heating various materials. There is a lot of trial and error involved with coming up with what works.

 

[Cind11]

I actually have a question about how a tourmaline "should" be heated...
Experts, please help me~thank you!

I have a unheated copper bearing tourmaline that has some grey in it, so I'd like to heat it myself at home...
Is it possible and how? And is it safe to do so?

I don't want to end up with a colorless stone or a cracked stone

I'll check my notes tonight, but I think I have heat the Mozambique material to 585 C which is 1085 F. Your normal oven can't go this high. I ramp up by changing the temperature 100 degrees per hour, hold the stone for 1 hour, then allow the oven to cool by it's self which is about 12 hours. The stone is packed in a crucible and investment powder. There is always the chance for the stone to crack. I have had some stones that were flawless crack, and I've had some with inclusions that didn't.

Gene - whilst you're looking at your notes, do you happen to know the temperature to heat Kunzite to please? I've got one that was once vibrant pink but is now almost colourless despite being in my safe and not exposed to sunlight ever I was very tempted to put it inside a chicken and cook in the oven but looking at your temperature guide for Tourmaline, I'm guessing that wouldn't work?

This is hysterically funny!! The thought of you cooking your kunzite inside a chicken in the oven!!! Hahahahaha!

 

[babydoll_mini]

I actually have a question about how a tourmaline "should" be heated...
Experts, please help me~thank you!

I have a unheated copper bearing tourmaline that has some grey in it, so I'd like to heat it myself at home...
Is it possible and how? And is it safe to do so?

I don't want to end up with a colorless stone or a cracked stone

I'll check my notes tonight, but I think I have heat the Mozambique material to 585 C which is 1085 F. Your normal oven can't go this high. I ramp up by changing the temperature 100 degrees per hour, hold the stone for 1 hour, then allow the oven to cool by it's self which is about 12 hours. The stone is packed in a crucible and investment powder. There is always the chance for the stone to crack. I have had some stones that were flawless crack, and I've had some with inclusions that didn't.

Dear Gene, thank you for your kindly reply! But I think I will give up on trying to heat my Mozambique at home (at my friend's home actually, who has an oven for cake baking, and I don't even have any oven...). Not to mention I have no idea what "crucible and investment powder" is. The process just sounds too risky for me.

But thank you anyway very much!!

 

[Arkteia]

I actually have a question about how a tourmaline "should" be heated...
Experts, please help me~thank you!

I have a unheated copper bearing tourmaline that has some grey in it, so I'd like to heat it myself at home...
Is it possible and how? And is it safe to do so?

I don't want to end up with a colorless stone or a cracked stone

I'll check my notes tonight, but I think I have heat the Mozambique material to 585 C which is 1085 F. Your normal oven can't go this high. I ramp up by changing the temperature 100 degrees per hour, hold the stone for 1 hour, then allow the oven to cool by it's self which is about 12 hours. The stone is packed in a crucible and investment powder. There is always the chance for the stone to crack. I have had some stones that were flawless crack, and I've had some with inclusions that didn't.

Gene - whilst you're looking at your notes, do you happen to know the temperature to heat Kunzite to please? I've got one that was once vibrant pink but is now almost colourless despite being in my safe and not exposed to sunlight ever I was very tempted to put it inside a chicken and cook in the oven but looking at your temperature guide for Tourmaline, I'm guessing that wouldn't work?

This is hysterically funny!! The thought of you cooking your kunzite inside a chicken in the oven!!! Hahahahaha!

Would make a nice stuffing, I think.

 

[Arkteia]

iLander - before Topaz was regulated there was a huge batch in the US (I think in the 90s sometime) that were waaaayyyyy of the scale when tested by a Geiger counter. Consequently, huge amounts were quarantined to cool down before they could be sold and I believe that's when more stringent regulations came in. I think, if I remember correctly, it was limited to London Blue Topaz and (I think) Sky Blue Topaz. So, it might be possible that some of the material was sold beforehand.

iLander, if you're really concerned, I'd definitely take the whole lot to be tested somewhere - it would beat blindly throwing out a lot of pieces that may have sentimental value. I bought blue topaz in the 90's too, but have had no ill effects. I've never worried about it, but I guess I'd be curious to know if there was any measurable radiation.

I have called my (tiny town) fire department and they are trying to find their geiger counter. They will call me back once they find it and have replaced the batteries . . .

I used to live in a bigger town, and I own a staff badge from the Manhattan Project. I took it to the local fire department and they checked it for me. The ambient radiation of the environment had to be compensated for, but the counter said the badge was fine. What shocked me was how high the ambient radiation was . . .

If you have a friend who is a biochemist, ask if he/she or his/her friends have them in their lab. The devices they are use are way more sensitive.

 

[Arkteia]

Personally, I assume that heated corundum or even Be-treated corundum may become an expensive thing once natural deposits are exhausted... and it is going to happen for sure. My problem, like anyone else's, is disclosure. It is my choice to buy Be-treated corundum and set it in diamonds, if I want to, but I have to know that I am paying fair price for the corundum and the diamond melee. So again, it comes to disclosure.

We depend on our trusted vendors. But can a trusted vendor make a mistake? Surely; he trusts his supplier. Can a supplier be mistaken? Certainly. It is important because any treatment decreases the cost of the stone. I wonder if it would be easier for our vendors to supply AGL certificates with their stones over $ 500.00. They probably get merchant's discounts on appraisals. I'd rather pay extra for the stone with an appraisal. So far, only Jeff White and Brad from the GemTrader supplied AGL certificates with their stones. And Tan, of course, if you ask him.

 

[PrecisionGem]

I took a few stones to the AGL about 2 years ago, and got certs on them, with the thought it would help to sell them. Well, it didn't seem to make any difference, and the people who eventually ended up buying the stones didn't seem to care about the cert at all. Maybe the cert only makes sense on certain stones?

 

[ForteKitty]

Sorry for the stupid questions, but if rubellites are irradiated, are they done w/ the same type of radiation used on topazes?

 

[chrono]

Crasru,
Not everyone knows about treatments and perhaps some don’t even care (or understand how it affects value). A middle ground solution to your question is to have the vendor send the stone for certification at the buyer’s expense. If it turns out to have some unexpected treatment on it, then the vendor accepts the cost of the lab memo. I also agree with Gene that it doesn’t make sense to have some variety of gemstones sent to the lab for testing because there is no treatment for them….yet.

 

[Michael_E]

but I have to know that I am paying fair price for the corundum and the diamond melee.

How do you know if what you're paying is a "fair" price? It's hard to find sapphires which are advertised as treated and so getting an accurate comparison to gauge price is exceptionally difficult. Getting comparative prices on melee is a bit easier, but these will soon, (if not already), be available as synthetic diamonds which are too small to consider testing due to the costs of testing. Does this matter? I'm not trying to be critical of your decision making, but am very interested in how you and others arrive at what you consider a fair price and what your reaction will be when the line between natural, treated and synthetic becomes blurred for many gems.

We depend on our trusted vendors. But can a trusted vendor make a mistake? Surely; he trusts his supplier.

Mistakes? Do you mean in claiming that a stone is untreated? This is definitely possible, but unless a lack of treatment is obvious and visible, a buyer and their vendor really do need to assume that a stone has been treated, particularly for the most attractive and expensive stones. The easiest way to avoid the problem is to assume, and state, that everything that can be treated, has been treated, if it doesn't have a cert, (or be able to show obvious traits which prove a lack of treatment).

It is important because any treatment decreases the cost of the stone.

This is definitely not the case. Gems are treated in order to increase their value. Treated stones may be worth less than a similar stone which is untreated, but they are all worth much more that they would have been if left untreated. At certain price levels it's just not worth the effort and expense of getting certs or even worrying about how a stone has been treated. I've had lots of people ask about certs on stones which are priced in the $100 to $200 level. This is just very strange to me since at this level a person is not even close to making an "investment", (meaning being able to get some future return on their investment), and, I would have thought, only been concerned about getting something pretty and well done. Why do they even care at this price level?

I wonder if it would be easier for our vendors to supply AGL certificates with their stones over $ 500.00. They probably get merchant's discounts on appraisals. I'd rather pay extra for the stone with an appraisal. So far, only Jeff White and Brad from the GemTrader supplied AGL certificates with their stones. And Tan, of course, if you ask him.

Maybe, BUT it only applies to some stones, mostly sapphires. Even with sapphires, there are very few wholesalers who provide certs from prominent labs until the price rises to several thousand dollars. With most everything else evidence of treatments is often inconclusive and so a cert is worthless. Why bother getting a cert on a tourmaline, garnet, beryl, zircon or spinel? You can assume that the most expensive tourmalines have been treated. The rest aren't aren't treated in any way that can be discerned through common gemmological tests and so there is no price difference between treated and untreated.

 

[T L]

The rest aren't aren't treated in any way that can be discerned through common gemmological tests and so there is no price difference between treated and untreated.

That's why I've decided to stay away from pink and blue tourmaline, since there is no definitive way (that I know of) to tell the difference between a nuked one and one that is natural in color. I have a big issue paying the same price for a nuked and non-treated stone, if the color is the same, and all else is equal. I'm pretty much done with tourmaline (time to change my PS handle name) as I only like blues and pinks, and I don't want to bother with any other color. Blues and pinks are the ones most commonly nuked

 

[ForteKitty]

Re: nuked tourmalines.. would you be weary of buying from reputable cutters? Can they nuke roughs? i recently bought a blue-green one...

 

[T L]

Re: nuked tourmalines.. would you be weary of buying from reputable cutters? Can they nuke roughs? i recently bought a blue-green one...

This will be a controversial answer, but knowing what I know, yes, I would be weary about buying a blue or pink tourmaline from ANY dealer, no matter how reputable. Call me paranoid, but even the most trusted sellers can be duped. If you can't even test for the treatment, then why bother buying the stone, unless it's super cheap and you don't care. At least you can test for filling, synthetics, diffusion, heating, but irradiation is altogether different. A lab report from a REPUTABLE and VERIFIABLE laboratory that has the appropriate equipment to test for specific treatment is a necessity if you're paying a high price and/or the knowledge of treatment is important to you.

Now if someone can tell me how you know a pink or a blue tourmaline can be checked to ensure it hasn't been irradiated, I would love to know. Having a trusted seller with a trusted supplier doesn't work for me, sorry. I've been trying to find out the answer to the above question for a while now from a reputable and highly expert source, no luck. And yes, I heard they're nuking rough, not just cut stones. I did hear that nuked tourmalines exhibit no color shift, but I only heard that from one place, Jeff Graham's site, faceters.com, and not from a lab, or the LMHC, and to me, that's not sufficient.

 

[ForteKitty]

now these nuked tourmalines.. is it radioactive like nuked topazes? I bought some from ds and bb and now i'm wondering if i should be worried...

 

[cellentani]

I know inclusions can't be used as a definitive marker for treatments, and we've already established that tourmaline is heated at temps far too low to melt rutile, but what about water or gas-filled inclusions? At what temperature would they rupture, and would it depend on the material, e.g., would these types of inclusions rupture at a lower temperature in tourmaline than in sapphire?

 

[T L]

now these nuked tourmalines.. is it radioactive like nuked topazes? I bought some from ds and bb and now i'm wondering if i should be worried...

I'll find out and get back to you.

Here's a webpage from pala on irradiation techniques in the meantime.
http://www.palagems.com/blue_topaz_weldon.htm

What's also really frustrating is that I've only seen photos of irradiated pink tourmalines, no blue ones. I have asked around too.

 

[ForteKitty]

I looked at that too, but not sure if i even believe that topazes can really be "safe", you know? and my birthstones is tourmaline, so i actually have quite a few. mostly green ones and some pink ones.. and a lot of the very included ones strung into bracelets. should i take them in to get tested?

 

[T L]

now these nuked tourmalines.. is it radioactive like nuked topazes? I bought some from ds and bb and now i'm wondering if i should be worried...

See the last post in this thread from Digital Devo.
https://www.pricescope.com/community/threads/why-is-nuking-unsafe.149967/

 

[ForteKitty]

Good to know, thank you!

eta: wait, does that mean your beautiful paraibas might be nuked too?

 

[Michael_E]

Good to know, thank you!

eta: wait, does that mean your beautiful paraibas might be nuked too?

In one way or another almost all of your beautiful gems have been nuked. This doesn't mean that a person did it, but any gem which grew in a pegamatite or formed in granite, has been exposed to radiation for millions of years. The great bulk of this radiation is in the form of gamma rays which are a more energetic form of X-rays. They do not do not produce any residual radiation in gems, food or anything else because they don't affect the nucleus of the atoms that they interact with. Using this form of radiation to produce a color change in a gem is quite safe, but may not be permanent, (depending on the gem). Although it may interfere with some peoples aesthetic sense it can certainly produce some stunningly beautiful gems from materials that would otherwise have very low values.

Although some would consider this sort of treatment a negative thing, it does provide a lot of fine material which has only been an improvement. In my view this is just one step up from cutting, (which is a treatment that many mineral collectors look down upon), and is definitely not making the material closer to being a synthetic in any sense. The idea behind having and wearing gems is to have something which is beautiful, durable and unique, (most treatments do produce unique outcomes, much more so than the highly controlled colors in synthetics). Using some treatments such as heat, diffusion, or irradiation is a valid and useful means of getting all of those attributes of a gem, while still maintaining it natural form, (as opposed to synthetics which no longer have their natural form). While the prices for treated materials "should" usually be lower than their more natural similarly colored siblings the aren't always.

Take it or leave it, but thumbing ones nose at some absolutely beautiful treated gems based on the treatment method used, seems a bit like throwing the baby out with the bathwater.

 

[ForteKitty]

I think you misunderstood me. I just dont want to start growing an 11th finger because of wearing a radioactive gem, so I wanted to understand the treatments a little more.

 

[Michael_E]

Radiation comes in several forms and the form used to change colors in gems does NOT leave any residual radiation coming from the gem. If they did most of the cutters in the world would be goners long before your 11th finger started growing. I've never heard of any gems used in jewelry ever posing a problem with residual radioactivity.

 

[iLander]

Well, for my own peace of mind, I'm going to have my MIL's pile of blue topaz checked.

My small-town fire department did call back, their geiger counter has been found, but isn't actually working anymore.

I'll have to take it to the next-biggest town, and I'll report back.

 

[T L]

Good to know, thank you!

eta: wait, does that mean your beautiful paraibas might be nuked too?

I bought them a long time ago, so I don't know when this treatment began on blue tourmaline (does someone know?). I know that the ones with needles tended to be heated, not nuked, and they did come with GIT memos that stated they contained copper, but can I say I know 100% for sure they have not been nuked, no I cannot.

It's so frustrating because there's no photos of irradiated indicolites out there for me to even compare visually (not like that would make much of a difference, but I'm curious).

Also note that tourmalines are also fracture filled these days, and paraibas are prone to that.

I have a violet copper bearing tourmaline, and as far as I know, that color is not heated or treated, unless you want to turn it blue.

 

[T L]

Take it or leave it, but thumbing ones nose at some absolutely beautiful treated gems based on the treatment method used, seems a bit like throwing the baby out with the bathwater.

Some people are purists. It's like the ones that want the real Van Gogh vs. the painted copy.

Beautiful natural untreated gems are a gift of Mother Earth, and it means a lot to some people to have a gem that's only been faceted, and nothing more. I do own some treated gems, so I'm not a purist like some people, but I stop at irradiated gems. That is just going a bit to far for my taste. It dramatically alters the color of the gem, and that disturbs me. I also won't buy diffused, coated or lead glass filled gems. I've lightened my stance on emeralds with faint to moderate resin filling after reading about this treatment, and I do have heated gems.

 

[Arkteia]

but I have to know that I am paying fair price for the corundum and the diamond melee.

1)

We depend on our trusted vendors. But can a trusted vendor make a mistake? Surely; he trusts his supplier.

Mistakes? Do you mean in claiming that a stone is untreated? This is definitely possible, but unless a lack of treatment is obvious and visible, a buyer and their vendor really do need to assume that a stone has been treated, particularly for the most attractive and expensive stones. The easiest way to avoid the problem is to assume, and state, that everything that can be treated, has been treated, if it doesn't have a cert, (or be able to show obvious traits which prove a lack of treatment).

- So if you ask a vendor whether the stone has been treated, and he does not know, he should say, "assume every stone has been treated", and not state that it has NOT been treated, unless he knows for sure. So unless someone got into a mine and dug it out himself (and even this is not "for sure"), at least has a certificate from a reputable lab. stating treatment or lack thereof would be appreciated. I stopped trusting "dealers' certificates" or "merchants' certificates". And when I am stating this, I am not targeting PS best vendors who mostly cut their own stones. In fact, they do not sell in bulk and may try to save every dollar because their markup is not high, hence no certificates. (Although they should be able to see the telltale signs of heating ).

But bulk sellers with huge websites and high markups should probably obtain certs for stones above $ 1000.00 just because they are making much more from their sales. I would not hold grudges against any of our best cutters for a random honest mistake, but I cringe when I see huge websites with sky-high prices and words "dealer's certificate" below a stone being sold at 7K! And do you remember PS discussions about the time period and the fact that the burden of proof lies with the buyer? Why? And what normal buyer can certify a stone with AGL within 7 days? 7 days should apply only to situations when the buyer changed his mind for whatever reason. (Now of course 7 days is an overkill, but this is exactly what some vendors do. 7 days if the stone has been misrepresented).


2)

It is important because any treatment decreases the cost of the stone.

This is definitely not the case. Gems are treated in order to increase their value. Treated stones may be worth less than a similar stone which is untreated, but they are all worth much more that they would have been if left untreated. At certain price levels it's just not worth the effort and expense of getting certs or even worrying about how a stone has been treated. I've had lots of people ask about certs on stones which are priced in the $100 to $200 level. This is just very strange to me since at this level a person is not even close to making an "investment", (meaning being able to get some future return on their investment), and, I would have thought, only been concerned about getting something pretty and well done. Why do they even care at this price level?

- Sad to admit, but you are right and most stones these days are treated in one way or another, and since "honest" technology usually lags behind, it will be very difficult to prove that our stones are "untreated". But: we expect to pay a PREMIUM for lack of treatment. It does not mean that I am expected to pay more for a 3-ct. unheated sapphire from Tanzania than 17-ct. heated-only sapphire from Ceylon (of similar color, of course), but how much would the price for a Mogok Tract unheated Burmese compare to a composite, let's say, H(a) ruby from Mong Hsu? Assuming similar color and size? "Treatment decreases the cost of the stone" was wrong formulation, I should have said, "all other parametres being equal, an untreated stone costs more than a treated one".

As to certifying a cheapo stone... Well, if it is bought at Tan's website, it is a cheapo. $ 36.00 for red spinel. Another stone, bought here, of same size, better cut, cleaner, $ 200+ ... color misrepresented on the photo. Looked pink-red, appeared to be red-brown. About 6 x difference. May eventually work for a side stone. Not a cheapo.

Neither had a certificate. Now, setting a small but pretty stone so that it would play costs something. I want to have a ring, and a nice one. If you browse ETSY website, you'll see that the price will be way above the cost of the stone. It is not an investment, but it may be resellable or upgradable. Given abundance of synthetic spinels, and the color of this one, won't hurt to cert it.

3 -

I wonder if it would be easier for our vendors to supply AGL certificates with their stones over $ 500.00. They probably get merchant's discounts on appraisals. I'd rather pay extra for the stone with an appraisal. So far, only Jeff White and Brad from the GemTrader supplied AGL certificates with their stones. And Tan, of course, if you ask him.

Maybe, BUT it only applies to some stones, mostly sapphires. Even with sapphires, there are very few wholesalers who provide certs from prominent labs until the price rises to several thousand dollars. With most everything else evidence of treatments is often inconclusive and so a cert is worthless. Why bother getting a cert on a tourmaline, garnet, beryl, zircon or spinel? You can assume that the most expensive tourmalines have been treated. The rest aren't aren't treated in any way that can be discerned through common gemmological tests and so there is no price difference between treated and untreated.

- because garnets are fracture-filled. Because demantoids are heated and until recently, big-time dealers were charging a premium for unheated demantoids without bothering to obtain certificate stating "no treatment". I am not going to dwell on it, several times I have posted my demantoid saga, and now heat-treatment of demantoids has been acknowledged by the same big-time dealers. (I am not even mentioning Tiffany, with its sellers, who just say, "Tiffany does not accept any treatment of its stones" ( ).) Because spinel may be heated in an attempt to clarify it and probably is, and several years down the road, heated spinel would cost less than the unheated one. And what should I do with my certs from AGL stating that "spinel is not commonly treated"? Because tourmalines have been colored. As to zircon... sorry. Nice stone; just not my cup of tea.

4 - How do you know if what you're paying is a "fair" price? It's hard to find sapphires which are advertised as treated and so getting an accurate comparison to gauge price is exceptionally difficult. Getting comparative prices on melee is a bit easier, but these will soon, (if not already), be available as synthetic diamonds which are too small to consider testing due to the costs of testing. Does this matter? I'm not trying to be critical of your decision making, but am very interested in how you and others arrive at what you consider a fair price and what your reaction will be when the line between natural, treated and synthetic becomes blurred for many gems.


- Fair price for Be-treated sapphires should probably be 5-15 $/ct at most. At least I am not prepared to pay more. But when I see general public buying from B@M stores with less-than-educated sellers or wholesale clubs where a guy who sells TVs is equally equipped to sell you a sapphire ring, I feel bad. Because neither the buyer nor the seller have any clue about Be treatment or any treatment whatsoever and sapphires are expensive everywhere.



Sadly, though, you are right, assume every stone is treated unless stated otherwise. Question, to which degree and whether the effect is permanent. Unless I know that it is permanent ... and most treatments have not been available for long enough to be sure...

 

[LD]

Good to know, thank you!

eta: wait, does that mean your beautiful paraibas might be nuked too?

I may be well off base here but I suspect (and I think TL may agree) that nuking of Tourmaline probably wasn't common when we were both collecting our Cuprian/Paraiba Tourmalines. Interestingly however, the material on the market now (with few exceptions) is very poorly saturated and pale rather than neon. To me, that suggests non-nuking but .......... who knows!

I believe that the irradiation applied to London Blue Topaz was very different from the other type of safe irradiation that is more commonly used in gems (and other shades of Topaz). I don't know why London Blue was treated differently. Perhaps one of our experts can comment.

 

[T L]

I believe that the irradiation applied to London Blue Topaz was very different from the other type of safe irradiation that is more commonly used in gems (and other shades of Topaz). I don't know why London Blue was treated differently. Perhaps one of our experts can comment.

It is treated differently in order to get the deeper, darker blue color of London Blues from what I understand.