Blue Zircon Where?

[mastercutgems]

Well I want to clarify something on the blue zircon...

Anyone knowing the art of heating red/brown Cambodian zircon can look in Kurt Nassau''s book on gemstone enhancement and see that you are taking the red/brown zircon to 150 degrees C and it will go to a red/orange or to a grayish brown; then you take the reddish brown and heat reducing to 1000 degrees C to get either the yellow to red or colorless or blue. Also if the color blue is not the best they take it to 900 degrees C exposed to air to better intensify the color. The first is done in charcoal; and if anyone out there has ever heated even tanzanite which is 800 degree F they will know that any inclusion, veil, or feather will intensify itself 5 fold if it does not crack in to. So inclusions in zircon and other gems most of the time will not take such heat... or if they do they will leave indicators of the heat process.

The rough crystals in which I still have a few are a medium to light blue still in their crystal formation and many have feathers and internal crystals that I am sure would split or expand to a fracture point at such temperature or halo out. Also you will see in my description they were bought as unheated as that was why I bought them as I was and am a collector and that was the reason of buying them as most are heated and these did not seem to be by laboratory analysis due to their internal crystal and other typical inclusions that will expand when heated to those temperatures. Plus you also learn to trust the integrity of the person you are buying from and this dealer was very well schooled in the treatment of gems; especially from the far east. If I was looking to buy the best color blue in zircon it would not have been those crystals...

I just wanted to make that clear as there seemed to be some skepticism in my being able to know if the gem had or not been heated.

Not worth the money to send to AGTA for an analysis; but I do know they are in nature just like blue topaz; but they are not the knock your socks off intense blue like the heated ones I have seen both cut and in rough.

Just wanted to clarify or quantify how I reached my judgement on the mineral being heated or unheated.. No disrespect intended

 

[katebar]

Stone Hunter and Chrono and Mastercutgems thanks for your expert input.
Kismet that''s reassuring.
Deia I am waiting to hear back fro Sally

 

[morecarats]

Date: 10/15/2009 12:22:48 PM
Author: mastercutgems
Well I want to clarify something on the blue zircon...

Anyone knowing the art of heating red/brown Cambodian zircon can look in Kurt Nassau''s book on gemstone enhancement and see that you are taking the red/brown zircon to 150 degrees C and it will go to a red/orange or to a grayish brown; then you take the reddish brown and heat reducing to 1000 degrees C to get either the yellow to red or colorless or blue. Also if the color blue is not the best they take it to 900 degrees C exposed to air to better intensify the color. The first is done in charcoal; and if anyone out there has ever heated even tanzanite which is 800 degree F they will know that any inclusion, veil, or feather will intensify itself 5 fold if it does not crack in to. So inclusions in zircon and other gems most of the time will not take such heat... or if they do they will leave indicators of the heat process.

The rough crystals in which I still have a few are a medium to light blue still in their crystal formation and many have feathers and internal crystals that I am sure would split or expand to a fracture point at such temperature or halo out. Also you will see in my description they were bought as unheated as that was why I bought them as I was and am a collector and that was the reason of buying them as most are heated and these did not seem to be by laboratory analysis due to their internal crystal and other typical inclusions that will expand when heated to those temperatures. Plus you also learn to trust the integrity of the person you are buying from and this dealer was very well schooled in the treatment of gems; especially from the far east. If I was looking to buy the best color blue in zircon it would not have been those crystals...

I just wanted to make that clear as there seemed to be some skepticism in my being able to know if the gem had or not been heated.

Not worth the money to send to AGTA for an analysis; but I do know they are in nature just like blue topaz; but they are not the knock your socks off intense blue like the heated ones I have seen both cut and in rough.

Just wanted to clarify or quantify how I reached my judgement on the mineral being heated or unheated.. No disrespect intended

Dana, since you appear to have a material that no one else has -- even those high end collector types at Palagems -- I don''t really understand your reluctance to have it certified at a gemological lab. Of course it will cost some money, but you''ll get the cost back (and probably more) when you sell the stone.

By way of illustration, I recently had some unheated orange pink sapphire that I thought should qualify as padparadscha. But there is so much pseudo padparadscha in the market that I didn''t want my customers to have to trust my word on it. So I sent it to a well-known lab for testing. It was certified as padparadscha and I was able to ask an appropriate price for it. The customer was happy since she had independent verification; I was happy since I got a fair price on the gem and recouped the cost of the testing.

 

[chrono]

MC,
For stones that the asking price goes up significantly, it makes sense to spend the money on certification. I''m not sure how much extra an unheated blue zircon will go for if the colour isn''t really outstanding, as Dana mentioned. Throw in the shipping and $25 AIGS brief, and it might be a wash.

 

[morecarats]

We see a lot of blue zircon here in Thailand, and I''ve yet to find anyone who has seen unheated material. That suggests it is exceedingly rare and thus worth a lot. It is certainly worth having it tested. I would think any lab would be very interested in getting their hands on it.

 

[mastercutgems]

Katebar;

You are more than welcome; and as for setting the zircon in a ring and even bezel setting I would just treat it like an opal, tanzanite, etc. as I have re-cut many for the trade that came back after a few years of wear with lots of abrasions. I also know some that have been worn for years that also look very good; but it is not their everyday ring.

I know I got one in that had to be low zircon as it was about 4 on the mohs scale in one zone and 6.5 in another. It had a huge chunk out of one corner. Fortunately I managed to salvage one section of it; but it did weigh 23 carats when I got it and it had to have lost over a carat in the accident. We did manage to get the Lady to put it in a pendant as when they start their downhill toward low zircon they can be very soft and fragile...

But if you do set it; wear it with care; dinner engagements, etc. and I think you will be fine. They do make lovely ring gems and I do like the intense blue ones... I do not think I would be digging in the garden with it though

MC;

You may want to check around some more as I have 3 other collectors that have the pastel blue unheated zircons in their collection; it was not man heat but ground radiation, or earth heat; as one has a bicolor of white and blue. 2 of the 3 are GG''s and they all tested no high heat or evident heat; I will try to look in my notes and get you the mine location.

They really do not fetch a high price in that pastel blue color; heated or unheated... But thanks for posting so much about it as another GG bought it along with one of the terminated crystals from that parcel with a gas bubble inclusion; he is really looking forward to adding it to his collection; not for it''s intrinsic value; but just because it is neat...

Just because you do not see a particular color of a gem mineral on the market today; does not mean it was ever discovered; as most gem websites carry what is in demand or what they feel they can easily sell; and pastel blue zircons in sizes less than 10 carats are really not in demand in this country.

And a sub 3 carat pastel blue zircon is surely not in the same league as a pad sapphire or spinel

But if you want to spend 50 dollars and a couple of hours in posting and shipping on a lab report for a 60 dollar gem that is totally up to you

But if it is ground radiation or earth heat you are not looking at a basic lab report; that could get very expensive. So please do not compare a pad sapphire to a pastel blue zircon; it is not fair to the zircon

 

[katebar]

Just got a message from Sally. She would only bezel the zircon. But she says she can get sapphires for a great prize and in the electric blue I want so we shall see!

 

[katebar]

Thanks again Mastercutgems you really have been very helpful!

 

[morecarats]

Date: 10/15/2009 12:22:48 PM
Author: mastercutgems
Well I want to clarify something on the blue zircon...

Anyone knowing the art of heating red/brown Cambodian zircon can look in Kurt Nassau''s book on gemstone enhancement and see that you are taking the red/brown zircon to 150 degrees C and it will go to a red/orange or to a grayish brown; then you take the reddish brown and heat reducing to 1000 degrees C to get either the yellow to red or colorless or blue. Also if the color blue is not the best they take it to 900 degrees C exposed to air to better intensify the color. The first is done in charcoal; and if anyone out there has ever heated even tanzanite which is 800 degree F they will know that any inclusion, veil, or feather will intensify itself 5 fold if it does not crack in to. So inclusions in zircon and other gems most of the time will not take such heat... or if they do they will leave indicators of the heat process.

The rough crystals in which I still have a few are a medium to light blue still in their crystal formation and many have feathers and internal crystals that I am sure would split or expand to a fracture point at such temperature or halo out. Also you will see in my description they were bought as unheated as that was why I bought them as I was and am a collector and that was the reason of buying them as most are heated and these did not seem to be by laboratory analysis due to their internal crystal and other typical inclusions that will expand when heated to those temperatures. Plus you also learn to trust the integrity of the person you are buying from and this dealer was very well schooled in the treatment of gems; especially from the far east. If I was looking to buy the best color blue in zircon it would not have been those crystals...

I just wanted to make that clear as there seemed to be some skepticism in my being able to know if the gem had or not been heated.

Not worth the money to send to AGTA for an analysis; but I do know they are in nature just like blue topaz; but they are not the knock your socks off intense blue like the heated ones I have seen both cut and in rough.

Just wanted to clarify or quantify how I reached my judgement on the mineral being heated or unheated.. No disrespect intended

Dana, to follow up on our discussion, I consulted with Dr. Laurent Massi, director of the testing lab at AIGS in Bangkok. I asked him if he had ever seen any samples of unheated blue zircon. He said he had not. Like a good scientist, he ackhowledged that it might exist, but thus far he had he not seen one. He said that the only natural bluish zircon he was familiar with is the rare green to blue color change zircon from Burma.

I think it''s fair to conclude that you have something very rare indeed. Or perhaps you just have heated blue zircon.