Natural Blue Topaz compared to treated??

[Candice]

Hi I bought an antique pear shaped blue topaz stone a few years back and just assumed it was treated to turn it blue. I was at my jewellers the other day and she asked to examine the ring. she stated that she believes that it is a natural blue topaz because of the colour and the inclusions within the stone.

I would love to learn more about natural versus treated blue topaz! approximately when did the industry start treating clear topaz to turn it blue, the worth of natural versus treated etc... I would love to know the approximate age of the stone or the cut off of when topaz treatments began.

thanks everyone

 

[morecarats]

With the current state of gemological science, some gem treatments are not detectable. The irradiation and subsequent low temperature heating of topaz is one such treatment. Neither the color of a blue topaz nor the presence of inclusions can show that the stone is untreated -- irradiated/heated topaz come in all shades of blue, and the heat treatment is usually done at a temperature that will not affect inclusions.

The irradiation of topaz required the technology of linear accelerators and nuclear reactors.

 

[ruffysdad]

I keep hearing of some kind of a test but have never seen anything that to me proves natural blue or irradiated blue. I just go on the assumption that it''s all irradiated and enjoy the color. The other thing I see is that "natural" rough costs way more than irradiated rough. Again, I just enjoy the color and look at the price. If they ever develop a test that can prove to my satisfaction that the stone was nuked in the ground I''ll be more than happy to pay the difference but so far I have yet to be convinced.

Pete

 

[Candice]

Date: 6/2/2010 11:38:32 AM
Author: ruffysdad
I keep hearing of some kind of a test but have never seen anything that to me proves natural blue or irradiated blue. I just go on the assumption that it''s all irradiated and enjoy the color. The other thing I see is that ''natural'' rough costs way more than irradiated rough. Again, I just enjoy the color and look at the price. If they ever develop a test that can prove to my satisfaction that the stone was nuked in the ground I''ll be more than happy to pay the difference but so far I have yet to be convinced.


Pete

I''ve had this stone set in a ring for 3 or 4 years now and I don''t care if its treated or not, I know its vintage and I love the cutting on it, nice big chunky facets on a big pear shape blue topaz yumm! honestly I dont even know if its 100% blue topaz it was sold as one with a jewellers appraisal, but not an independent lab cert. anyways I love my ring, i am just curious to hear any information regarding treatments and if there was a period where treatments started.
thanks!

 

[Indylady]

I'm certain that Modern Jeweler has an article on the advent and rise of treated blue topaz.

 

[Candice]

thanks IndyLady!

 

[Edward Bristol]

We are always looking for untreated topaz but I have never ever seen one that was really blue.

Light sky blue is the best there is, and a aqua green-blue. Anything topaz that has a stronger color we consider treated.

 

[Barrett]

I actually saw the best natural blue topaz I had ever seen this last week up in maine..it was in the collection of Bob Whitmore who owns the Palermo mine..almost a full crystal..must have been 600+cts..about 80% gem clean..had the color of a good aquamarine..My buddy scott got pics..will post them once he sends them..I think the size helped keep the color so good on it..it was brazilian

 

[Richard M.]

Date: 6/2/2010 8:40:24 AM
Author:Candice
approximately when did the industry start treating clear topaz to turn it blue, the worth of natural versus treated etc... I would love to know the approximate age of the stone or the cut off of when topaz treatments began.


thanks everyone

Hi Candice,

Treated blue topaz entered the U.S. market in the early 1980s. I saw the first such stones at the Tucson show in about 1980 or 81. So if your stone is substantially older than that it''s probably a natural blue. There''s no lab test yet that can differentiate treated from untreated gems. I did a lot of research on that recently because I was offering stones from a rather large deposit in Brazil said by several reliable sources to produce natural blues. I wanted to be sure.

Nearly all topaz localities produce some natural blues but they are seldom as saturate as the treated stones (there are several treatment processes that yield substantially different hues and tones). Most natural blues have come from Ceylon, Burma, Australia, Nigeria, Brazil, Russia, the Pike''s Peak region in the U.S. and Texas where it''s the state gemstone. High quality natural stones are rare and bring much higher prices than treated if their provenance can be proved. Unfortunately that may not be possible with your stone.

Richard M. (Rick Martin)

 

[Candice]

Thanks Richard,
the stone I have is a light blue and when the sun hits it it has "hints" of bright blue and a bit of pink. the stone isnt precision cut and you can tell because of the cutting, it almost looks like the pear version of an old mine cut or something. the auction house i got it from was from an estate that said the topaz was bought in the 50''s and they never said when it was cut, or didn''t have that information. thanks for the information!
best,
Candice