Chameleon tanzanite?

[nannieA]

Saw a piece last night,didn't quite know what to make of it except that it was very expensive.Too dear for me.

 

[Sacha]

Yes Jacqualina and Lynn did stress that these Tanzanites weren't coated and they apparently all come from Block C at Tanzanite 1.

She also said that many customers had contacted GemsTV about these new stones and to ask about treatments etc.
There were very limited numbers of each piece and most sold very rapidly, the show finished well within its allotted hour.

The prices were a bit less (not too much) than the 'shop' prices.

 

[jacqualina]

Thanks Sacha, I wonder if they were unheated tanzanites like the ones they used to sell in the good old days. How did they compare (aesthetically) to normal tanzanite?

 

[Sacha]

Hi again Jacqualina

I can't recall Lynn mentioning if they were heated / unheated, so I would assume they have been heated. Perhaps anyone else who was watching can confirm this?

The colours were interesting, mixture of blues, subtle pinks and sometimes splashes of green and the designs were pretty. I liked the ones with a bit of green in best, but each one would be individual even though set in the same design.

Lynn is in the studio today and is always happy to be emailed I believe. She may be able to offer more info for you perhaps.

 

[faerie]

hi

I was watching last night, when the 'only 2 in the world' rings were on last nighy (1 looks identical on the web just now, in the shop for 662.93 (went for 567 last night)

I heard them say - not word for word though, wasnt paying too much attention at the beginning, but, what I heard was

we all know tanzanite is heat treated. when its treated, it either goes the dark blue colour, the pale lilac colour, or this colour

then I started to listen coz I thought it made a difference where in the mine the stone was mined- (never seen an AAA pale lilac tanzanite) and it sold out. meant to watch it later, think there was more are 10pm but changed my mind

had liked it at the start, but then got confused and went off it a bit ...

 

[Meeshoo]

Errrrrrrrrrrrrrrrrr???????????

When Tanzanite is heated it drives off the browns, greens, pinks, yellows so I'm very very very very very very very confused!

I don't think I'll be touching this with a bargepole!

 

[nannieA]

Hi just read the post about andesine,this gal bought 2 last year,1 colour change and 1 imperial,has this been coated? I certainly wouldn't have bought it had I known. But then I hadn't discovered the wealth of knowledge which is now available on this forum.

 

[Richard Hughes]

Explanation of Chameleon Tanzanite

Complete and utter marketing hype and rubbish.

Some sellers are trying to sell Tanzanite by claiming that is has chameleon type qualities i.e. changes colour. Well of course it does. It's strongly trichroic so when it's viewed from different angles you get different shades of blue, purple, pink (and occasionally a red colour). To market it as a "chameleon" is misleading to the extreme. I believe Gems in the US have been trying to sell this for ages.

Don't fall for the hype - it's tosh and nonsense (words cleaned up considerably).


Edited to add: Just had a look at the website - the pictures are all photoshopped so you can't tell the real colour but if the Tanzanites are showing two colours i.e. blue/green then this suggests they're probably unheated material.

Hi everyone,

A friend passed along this link to me and I'd like to clear up some of the misstatements regarding chameleon tanzanite.

As many of you are aware, tanzanite may occur in both a blue/violet and, far more rarely, a green colour. Green tanzanite has been detailed in this excellent article in Gems & Gemology:

Gem Quality Green Zoisite.

The cause of colour in blue/violet tanzanite is vanadium, while in green tanzanite the cause of colour is believed to be a combination of chromium and vanadium.

GemsTV recently purchased a large lot of material that is zoned in both blue/violet and green colours. This is not pleochroism, but actual colour zoning, where parts of the gem are blue and other parts green. When we looked at this material, we were struck by the fact that every stone was different and unique, no two are alike. And as you move the stone or light, the colours shift and change. Thus we decided to call it chameleon tanzanite. It comes mainly from TanzaniteOne's Block C mine and is extremely limited in quantity.

Some have asked about treatments. Like virtually all other tanzanites, chameleon tanzanite is heat treated at approximately 500°C. The resulting colour is absolutely stable.

Regarding coated tanzanite, the GemsTV enhancements page is the most comprehensive in the industry. It lists all known enhancements for all types of gems, not just for gems that we carry. For the record, neither GemsTV nor Thaigem.com sells coated tanzanite.

I hope this clears up some of the misunderstandings regarding this fascinating gem. If you have further questions, just let me know.

Regards,
Richard W. Hughes
Senior V.P., Gemstone Marketing & Testing
NCS Group (GemsTV)

 

[anthony grishmann]

http://www.free-press-release.com/news/200807/1216293258.html


read this people

 

[anthony grishmann]

http://www.airesjewelers.com/Heat_Treatment_of_gemstones.htm


and this

 

[Meeshoo]

Hi everyone,

A friend passed along this link to me and I'd like to clear up some of the misstatements regarding chameleon tanzanite.

As many of you are aware, tanzanite may occur in both a blue/violet and, far more rarely, a green colour. Green tanzanite has been detailed in this excellent article in Gems & Gemology:

Gem Quality Green Zoisite.

The cause of colour in blue/violet tanzanite is vanadium, while in green tanzanite the cause of colour is believed to be a combination of chromium and vanadium.

GemsTV recently purchased a large lot of material that is zoned in both blue/violet and green colours. This is not pleochroism, but actual colour zoning, where parts of the gem are blue and other parts green. When we looked at this material, we were struck by the fact that every stone was different and unique, no two are alike. And as you move the stone or light, the colours shift and change. Thus we decided to call it chameleon tanzanite. It comes mainly from TanzaniteOne's Block C mine and is extremely limited in quantity.

Some have asked about treatments. Like virtually all other tanzanites, chameleon tanzanite is heat treated at approximately 500°C. The resulting colour is absolutely stable.

Regarding coated tanzanite, the GemsTV enhancements page is the most comprehensive in the industry. It lists all known enhancements for all types of gems, not just for gems that we carry. For the record, neither GemsTV nor Thaigem.com sells coated tanzanite.

I hope this clears up some of the misunderstandings regarding this fascinating gem. If you have further questions, just let me know.

Regards,
Richard W. Hughes
Senior V.P., Gemstone Marketing & Testing
NCS Group (GemsTV)

Mr Hughes

With the greatest of respect, and I mean that sincerely as I bow to your expert knowledge of rubies and sapphires, if the GemsTV presenters (or enhancements page) detailed the exact nature of chameleon tanzanite, there would be less misunderstanding?

There are, you understand I'm sure, a plethoria of sellers in the market place selling tanzanite by stating it to have "chameleon like qualities" when in fact those particular gemstones contain no green zoisite and the change is purely a result of trichroism. A very expensive piece of tanzanite was being marketed on this forum in just this way a year or two ago (not by GemsTV).

In terms of coated Tanzanite, I believe that GemsTV have (knowingly or unknowingly) sold at least 2 pieces of coated tanzanite (in 2008). The addition to the enhancements page appeared shortly thereafter. Therefore please forgive my cynicism when I see marketing of a gemstone without any explanation. I am however, very reassured that GemsTV do not at the current time sell coated Tanzanite. That being the case, perhaps the reference to coated Tanzanite should be removed from the enhancements page as its very inclusion is misleading.

As a matter of sincere interest I was wondering how the heat process to the chameleon tanzanite doesn't drive off the green colour? Certainly unheated green tanzanite is wonderful (personal preference) but I was always under the impression that once heated the green would convert to blue/purple in the same way that the brown is driven off. Is it due to the chromium/vanadium content being much higher than the "normal" unheated green Tanzanite? Does the zoning appear less pronounced after heating? Thank you in advance for your advice.

 

[Richard Hughes]

More on Chameleon Tanzanite

Mr Hughes

With the greatest of respect, and I mean that sincerely as I bow to your expert knowledge of rubies and sapphires, if the GemsTV presenters (or enhancements page) detailed the exact nature of chameleon tanzanite, there would be less misunderstanding?

There are, you understand I'm sure, a plethoria of sellers in the market place selling tanzanite by stating it to have "chameleon like qualities" when in fact those particular gemstones contain no green zoisite and the change is purely a result of trichroism. A very expensive piece of tanzanite was being marketed on this forum in just this way a year or two ago (not by GemsTV).

In terms of coated Tanzanite, I believe that GemsTV have (knowingly or unknowingly) sold at least 2 pieces of coated tanzanite (in 2008). The addition to the enhancements page appeared shortly thereafter. Therefore please forgive my cynicism when I see marketing of a gemstone without any explanation. I am however, very reassured that GemsTV do not at the current time sell coated Tanzanite. That being the case, perhaps the reference to coated Tanzanite should be removed from the enhancements page as its very inclusion is misleading.

As a matter of sincere interest I was wondering how the heat process to the chameleon tanzanite doesn't drive off the green colour? Certainly unheated green tanzanite is wonderful (personal preference) but I was always under the impression that once heated the green would convert to blue/purple in the same way that the brown is driven off. Is it due to the chromium/vanadium content being much higher than the "normal" unheated green Tanzanite? Does the zoning appear less pronounced after heating? Thank you in advance for your advice.

Thanks for your note. With regard to coated tanzanite being sold by GemsTV, can you please provide specifics? To the best of my knowledge, GemsTV has never sold coated tanzanite. Is this merely a rumour or do you have specific evidence? If you have specific evidence, I for one would like to know about it. Feel free to email me and rest assured I will treat it in confidence, if you request.

A quick note of caution about online forums. In my experience, they are often filled with wild speculation that has little or no basis in fact. This is particularly true with some of the recent comments seen about gem treatments.

Coated tanzanite was first identified in May of 2007 and I did personally examine the original lot of stones. They were brought to the AGTA lab by a dealer who had been told of the treatment by his supplier and wanted to alert the trade. As far as I know, there is only a tiny amount of material in the market.

With regard to the colour of blue/violet tanzanite, it is caused by vanadium. You can read more about it here:

Colour of Tanzanite

The colour of green tanzanite is thought to result from chromium. I would guess that the Cr⁺³ ion would substitute for the Al⁺³ ion in the zoisite structure, but have not studied the matter in depth. In the case of such a substitution, since the Cr is isovalent (has the same valence state) with Al, heating would probably not alter it. This is similar to the situation in ruby, where Cr substitutes for Al in an isovalent fashion.

So if Cr in ruby or tanzanite is not modified by heating, why heat a stone? Keep in mind that few crystals in nature are pure (our chameleon tanzanite being a classic example). More than likely, a green tanzanite also contains some vanadium and so heating could still produce changes in colour, although more subtle than in normal tanzanite. In the case of ruby, the red color is modified by blue (Fe + Ti charge transfer). Heating can remove the blue, thus leaving behind the pure red.

If you or others have questions, please feel free to contact me and I'll do my best to get you an answer.

 

[Richard Hughes]

Pictures of Chameleon Tanzanite

I thought some of you might like to see some pictures of chameleon tanzanite. Here you go:

Chameleon Tanzanite

Chameleon Tanzanite

Richard Hughes

 

[MissMagpie]

Thanks for that!

Well, I've taken the plunge... and I'm pleased to say that the ring I received today looks darker that any of the photos. Reckon I must have got a goodun! (OK, I cheated - sent for three and chose the best.)

Mostly, it just looks like tanzanite. But very nice tanzanite, a lovely setting and a good price, so I'm not complaining.

See, Gems - you CAN do it!

 

[jacqualina]

Well done MissM, any chance of a piccie or item number?

 

[gemcherub]

Glad your pleased with your ring and yes we need photos lol

 

[Oops-a-daisy!]

I'm pleased you found a good one Miss M. I'd love to see your photos.

I had one delivered this week too. Mine only looks like a Tanzanite at night (deep blue/purple), though it does change to a plum shade under lamplight. However, during the day it is green (changing from silver grayish green to Emerald to Alexandrite colours). Then the light changes and you get a big splash of violet in the centre with apricot colours at the side and in low lighting a big starburst of vivid pink. I'm totally mesmerized by this gemstone and can't stop looking at it.

 

[MissMagpie]

It was this one:

http://www.gemstv.co.uk/Shop/productDataSheet.jsp?productid=ULU3023

But after all that, I've decided to send it back!

Nothing wrong with it at all - it's lovely - but it just doesn't suit my hand. It think it's too small (the design I mean, not the ring size), and so I just won't wear it. It wasn't cheap, and I don't have money to burn.

But definitely recommended if anyone else wants it!

 

[gemcherub]

I'm pleased you found a good one Miss M. I'd love to see your photos.

I had one delivered this week too. Mine only looks like a Tanzanite at night (deep blue/purple), though it does change to a plum shade under lamplight. However, during the day it is green (changing from silver grayish green to Emerald to Alexandrite colours). Then the light changes and you get a big splash of violet in the centre with apricot colours at the side and in low lighting a big starburst of vivid pink. I'm totally mesmerized by this gemstone and can't stop looking at it.

Sounds beautiful and the fact that you can't stop looking at it sounds like you will wear and enjoy it a lot, any chance of a photo?

 

[Meeshoo]

I'm very glad for everybody that has received chameleon tanzanite and are delighted with it. Melusina - your description is wonderful- very many congratulations on finding a gemstone that you love so much. I have to admit that it's not something that I want - it's overpriced IMHO and I wouldn't say it would ever rival top grade tanzanite, pretty as it may be. I guess I'm a bit "Tanzanited" out!!!!

Richard Hughes - I don't repeat rumours or post speculatively on something so important. For confidentiality reasons I will not post on this website the source of my information. I am not in the habit of posting untruths and certainly, in this case, have not done so.